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  <xs:element id="acgl_ReinsuranceSegmentMember" abstract="true" name="ReinsuranceSegmentMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acgl_MortgageSegmentMember" abstract="true" name="MortgageSegmentMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acgl_ReinsuranceCoverageAndRetentionTableTextBlock" abstract="false" name="ReinsuranceCoverageAndRetentionTableTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType"/>
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  <xs:element id="acgl_VariableInterestEntityMaximumExposureToLossTableTextBlock" abstract="false" name="VariableInterestEntityMaximumExposureToLossTableTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType"/>
  <xs:element id="acgl_SummaryOfOpenTaxYearsPotentiallySubjectToExaminationByJurisdictionTableTextBlock" abstract="false" name="SummaryOfOpenTaxYearsPotentiallySubjectToExaminationByJurisdictionTableTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType"/>
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  <xs:element id="acgl_FiniteandIndefiniteLivedIntangibleAssetsByMajorClassTableTextBlock" abstract="false" name="FiniteandIndefiniteLivedIntangibleAssetsByMajorClassTableTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType"/>
  <xs:element id="acgl_ScheduleofSharebasedPaymentAwardOtherThanStockOptionsValuationAssumptionsTableTextBlock" abstract="false" name="ScheduleofSharebasedPaymentAwardOtherThanStockOptionsValuationAssumptionsTableTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType"/>
  <xs:element id="acgl_RestrictedCommonSharesAndRestrictedUnitsMember" abstract="true" name="RestrictedCommonSharesAndRestrictedUnitsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acgl_SharebasedCompensationArrangementbySharebasedPaymentAwardOtherThanOptionsGrantsinPeriodWeightedAverageGrantDateFairValueTableTextBlock" abstract="false" name="SharebasedCompensationArrangementbySharebasedPaymentAwardOtherThanOptionsGrantsinPeriodWeightedAverageGrantDateFairValueTableTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType"/>
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  <xs:element id="acgl_ReservesForLossesAndLossAdjustmentExpensesMember" abstract="true" name="ReservesForLossesAndLossAdjustmentExpensesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acgl_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndInvestments" abstract="false" name="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndInvestments" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="acgl_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPremiumsReceivable" abstract="false" name="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPremiumsReceivable" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
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  <xs:element id="acgl_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedReservesForLossesAndLossAdjustmentExpenses" abstract="false" name="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedReservesForLossesAndLossAdjustmentExpenses" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="acgl_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherLiabilities" abstract="false" name="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherLiabilities" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="acgl_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsLossReservesAndUnearnedPremiums" abstract="false" name="DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsLossReservesAndUnearnedPremiums" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
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  <xs:element id="acgl_SignificantAccountingPoliciesLineItems" abstract="true" name="SignificantAccountingPoliciesLineItems" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
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  <xs:element id="acgl_EquityMethodInvestmentsReportingLag" abstract="false" name="EquityMethodInvestmentsReportingLag" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="acgl_UnderwritingIncomeLossSegment" abstract="false" name="UnderwritingIncomeLossSegment" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="acgl_SegmentOtherCostAndExpenseOperating" abstract="false" name="SegmentOtherCostAndExpenseOperating" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
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  <xs:element id="acgl_OtherOperatingExpenseRatioPercentage" abstract="false" name="OtherOperatingExpenseRatioPercentage" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
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  <xs:element id="acgl_OtherLiabilityOccurrenceMember" abstract="true" name="OtherLiabilityOccurrenceMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acgl_OtherLiabilityClaimsMadeMember" abstract="true" name="OtherLiabilityClaimsMadeMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
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  <xs:element id="acgl_OtherProductsMember" abstract="true" name="OtherProductsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
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  <xs:element id="acgl_USCreditRiskTransferAndOtherMember" abstract="true" name="USCreditRiskTransferAndOtherMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
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  <xs:element id="acgl_EuropeAndOtherMember" abstract="true" name="EuropeAndOtherMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
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  <xs:element id="acgl_PropertyEnergyMarineAndAviationMember" abstract="true" name="PropertyEnergyMarineAndAviationMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acgl_OtherSpecialtyLinesMember" abstract="true" name="OtherSpecialtyLinesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acgl_WarrantyAndLendersSolutionsMember" abstract="true" name="WarrantyAndLendersSolutionsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
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  <xs:element id="acgl_ThirdPartyClaimsMadeBusinessMember" abstract="true" name="ThirdPartyClaimsMadeBusinessMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acgl_MultilineAndOtherSpecialtyMember" abstract="true" name="MultilineAndOtherSpecialtyMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
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  <xs:element id="acgl_ShortDurationLinesOfBusinessMember" abstract="true" name="ShortDurationLinesOfBusinessMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
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  <xs:element id="acgl_ShortDurationContractsLargeClaimSizeThreshold" abstract="false" name="ShortDurationContractsLargeClaimSizeThreshold" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="acgl_PremiumReceivableAllowanceForCreditLossProvisionForBusinessAcquired" abstract="false" name="PremiumReceivableAllowanceForCreditLossProvisionForBusinessAcquired" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="acgl_AmBestAminusOrBetterRatingMember" abstract="true" name="AmBestAminusOrBetterRatingMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
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  <xs:element id="acgl_LargestBalanceDueFromAnyOneCarrierMember" abstract="true" name="LargestBalanceDueFromAnyOneCarrierMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acgl_ContractholderReceivablesCreditLossExpenseReversal" abstract="false" name="ContractholderReceivablesCreditLossExpenseReversal" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
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  <xs:element id="acgl_Bellemeade20222LtdMember" abstract="true" name="Bellemeade20222LtdMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
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  <xs:element id="acgl_DirectlyProvidedCapacityMember" abstract="true" name="DirectlyProvidedCapacityMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acgl_InitialCoverageAmount" abstract="false" name="InitialCoverageAmount" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="acgl_AggregateExcessOfLossReinsuranceAgreement" abstract="false" name="AggregateExcessOfLossReinsuranceAgreement" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
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  <xs:element id="acgl_AvailableForSaleSecuritiesQualitativeDisclosureNumberOfPositions" abstract="false" name="AvailableForSaleSecuritiesQualitativeDisclosureNumberOfPositions" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
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  <xs:element id="acgl_UnderwritingRelatedAllowanceForCreditLossesCreditLossExpenseReversal" abstract="false" name="UnderwritingRelatedAllowanceForCreditLossesCreditLossExpenseReversal" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="acgl_OtherRealizedAndUnrealizedGainsAndLosses" abstract="false" name="OtherRealizedAndUnrealizedGainsAndLosses" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
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  <xs:element id="acgl_InvestmentGradeFixedIncomeMember" abstract="true" name="InvestmentGradeFixedIncomeMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acgl_OtherInvestmentsLendingMember" abstract="true" name="OtherInvestmentsLendingMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acgl_TermLoanInvestmentsMember" abstract="true" name="TermLoanInvestmentsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acgl_CreditRelatedFundsMember" abstract="true" name="CreditRelatedFundsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acgl_OtherInvestmentsEnergyMember" abstract="true" name="OtherInvestmentsEnergyMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acgl_ScheduleOfOtherInvestmentsLineItems" abstract="true" name="ScheduleOfOtherInvestmentsLineItems" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="acgl_FairValueOptionMember" abstract="true" name="FairValueOptionMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acgl_InvestmentCommitments" abstract="false" name="InvestmentCommitments" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="acgl_OtherInvestmentsInfrastructureMember" abstract="true" name="OtherInvestmentsInfrastructureMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
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  <xs:element id="acgl_CofaceMember" abstract="true" name="CofaceMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acgl_GreysbridgeHoldingsLtdMember" abstract="true" name="GreysbridgeHoldingsLtdMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acgl_IssuedSharesExcludingTreasuryStockMember" abstract="true" name="IssuedSharesExcludingTreasuryStockMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acgl_InvestmentInAffiliatePricePerShare" abstract="false" name="InvestmentInAffiliatePricePerShare" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types:perShareItemType"/>
  <xs:element id="acgl_ScheduleOfRestrictedAssetsTable" abstract="true" name="ScheduleOfRestrictedAssetsTable" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType"/>
  <xs:element id="acgl_SomersHoldingsLtdMember" abstract="true" name="SomersHoldingsLtdMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acgl_RestrictedAssetsRestrictionTypeAxis" abstract="true" name="RestrictedAssetsRestrictionTypeAxis" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType"/>
  <xs:element id="acgl_RestrictedAssetsRestrictionTypeDomain" abstract="true" name="RestrictedAssetsRestrictionTypeDomain" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acgl_CollateralOrGuaranteesAffiliatedTransactionsMember" abstract="true" name="CollateralOrGuaranteesAffiliatedTransactionsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acgl_CollateralOrGuaranteesThirdPartyAgreementsMember" abstract="true" name="CollateralOrGuaranteesThirdPartyAgreementsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acgl_DepositsWithUsRegulatoryAuthoritiesMember" abstract="true" name="DepositsWithUsRegulatoryAuthoritiesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acgl_DepositsWithNonUsRegulatoryAuthoritiesMember" abstract="true" name="DepositsWithNonUsRegulatoryAuthoritiesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acgl_RestrictedAssetsLineItems" abstract="true" name="RestrictedAssetsLineItems" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="acgl_RestrictedAssets" abstract="false" name="RestrictedAssets" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="acgl_ShortTermInvestmentsFairValueOptionMember" abstract="true" name="ShortTermInvestmentsFairValueOptionMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acgl_EquitySecuritiesFairValueOptionMember" abstract="true" name="EquitySecuritiesFairValueOptionMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acgl_OtherInvestmentsFairValueOptionMember" abstract="true" name="OtherInvestmentsFairValueOptionMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acgl_TotalAssetsAndLiabilitiesMeasuredAtFairValue" abstract="false" name="TotalAssetsAndLiabilitiesMeasuredAtFairValue" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="acgl_TotalAssetsAndLiabilitiesMeasuredAtFairValuePricedUsingNonBindingBrokerQuotes" abstract="false" name="TotalAssetsAndLiabilitiesMeasuredAtFairValuePricedUsingNonBindingBrokerQuotes" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="acgl_PercentageOfTotalAssetsAndLiabilitiesMeasuredAtFairValuePricedUsingNonBindingBrokerQuotes" abstract="false" name="PercentageOfTotalAssetsAndLiabilitiesMeasuredAtFairValuePricedUsingNonBindingBrokerQuotes" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="acgl_RemainingCoverageAmount" abstract="false" name="RemainingCoverageAmount" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="acgl_IncomeTaxDisclosureTable" abstract="true" name="IncomeTaxDisclosureTable" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType"/>
  <xs:element id="acgl_IncomeTaxDisclosureLineItems" abstract="true" name="IncomeTaxDisclosureLineItems" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="acgl_StatutoryTaxRatePercentage" abstract="false" name="StatutoryTaxRatePercentage" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="acgl_EffectiveIncomeTaxRateReconciliationForeignIncomeTaxOtherAmount" abstract="false" name="EffectiveIncomeTaxRateReconciliationForeignIncomeTaxOtherAmount" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="acgl_NontaxableOrNondeductibleAmountAbstract" abstract="true" name="NontaxableOrNondeductibleAmountAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="acgl_EffectiveIncomeTaxRateReconciliationForeignIncomeTaxOtherPercent" abstract="false" name="EffectiveIncomeTaxRateReconciliationForeignIncomeTaxOtherPercent" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="acgl_NontaxableIncomeNondeductibeExpensePercentAbstract" abstract="true" name="NontaxableIncomeNondeductibeExpensePercentAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="acgl_EffectiveIncomeTaxRateReconciliationUncertainTaxPositionAmount" abstract="false" name="EffectiveIncomeTaxRateReconciliationUncertainTaxPositionAmount" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="acgl_IncomeTaxReconciliationDividendWithholdingTaxes" abstract="false" name="IncomeTaxReconciliationDividendWithholdingTaxes" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="acgl_DeferredTaxAssetsDepreciationAndAmortization" abstract="false" name="DeferredTaxAssetsDepreciationAndAmortization" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="acgl_DeferredTaxAssetLeaseLiability" abstract="false" name="DeferredTaxAssetLeaseLiability" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="acgl_DeferredTaxAssetDiscountedDebt" abstract="false" name="DeferredTaxAssetDiscountedDebt" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="acgl_DeferredTaxAssetsAdvanceClaimPayments" abstract="false" name="DeferredTaxAssetsAdvanceClaimPayments" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="acgl_DeferredTaxLiabilityLloydsYearOfAccountDeferral" abstract="false" name="DeferredTaxLiabilityLloydsYearOfAccountDeferral" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="acgl_DeferredTaxLiabilityContingencyReserve" abstract="false" name="DeferredTaxLiabilityContingencyReserve" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="acgl_DeferredTaxLiabilitiesInvestmentRelated" abstract="false" name="DeferredTaxLiabilitiesInvestmentRelated" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="acgl_UnrecognizedTaxBenefitsChangeResultingFromSettlementsWithTaxingAuthorities" abstract="false" name="UnrecognizedTaxBenefitsChangeResultingFromSettlementsWithTaxingAuthorities" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="acgl_UnitedStatesOtherMember" abstract="true" name="UnitedStatesOtherMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acgl_U.S.MortgageGuarantyTaxandLossBondsMember" abstract="true" name="U.S.MortgageGuarantyTaxandLossBondsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acgl_PremiaHoldingsLtdMember" abstract="true" name="PremiaHoldingsLtdMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acgl_WatfordInsuranceCompanyMember" abstract="true" name="WatfordInsuranceCompanyMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acgl_NumberOfDirectors" abstract="false" name="NumberOfDirectors" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="acgl_GrossWrittenPremiumsMember" abstract="true" name="GrossWrittenPremiumsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acgl_MarshAndMclennanCompaniesMember" abstract="true" name="MarshAndMclennanCompaniesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acgl_AONCorporationAndSubsidiariesMember" abstract="true" name="AONCorporationAndSubsidiariesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acgl_ConcentrationRiskThresholdPercentage" abstract="false" name="ConcentrationRiskThresholdPercentage" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="acgl_SeniorNotesDue2034Member" abstract="true" name="SeniorNotesDue2034Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acgl_SeniorNotesDue2043Member" abstract="true" name="SeniorNotesDue2043Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acgl_SeniorNotesDue2026Member" abstract="true" name="SeniorNotesDue2026Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acgl_SeniorNotesDue2046Member" abstract="true" name="SeniorNotesDue2046Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acgl_SeniorNotesDue2050Member" abstract="true" name="SeniorNotesDue2050Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acgl_ArchReBermudaMember" abstract="true" name="ArchReBermudaMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acgl_CreditAgreementMember" abstract="true" name="CreditAgreementMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acgl_SecuredLetterOfCreditFacilityMember" abstract="true" name="SecuredLetterOfCreditFacilityMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acgl_UnsecuredRevolvingLoanAndLetterOfCreditFacilityMember" abstract="true" name="UnsecuredRevolvingLoanAndLetterOfCreditFacilityMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acgl_UnsecuredLetterOfCreditFacilityMember" abstract="true" name="UnsecuredLetterOfCreditFacilityMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acgl_LloydsFacilityMember" abstract="true" name="LloydsFacilityMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acgl_OtherLetterOfCreditFacilitiesMember" abstract="true" name="OtherLetterOfCreditFacilitiesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acgl_LineOfCreditFacilityOptionalIncreasedCapacity" abstract="false" name="LineOfCreditFacilityOptionalIncreasedCapacity" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="acgl_ScheduleofGoodwillAndIntangibleAssetsTable" abstract="true" name="ScheduleofGoodwillAndIntangibleAssetsTable" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType"/>
  <xs:element id="acgl_ScheduleofGoodwillAndIntangibleAssetsLineItems" abstract="true" name="ScheduleofGoodwillAndIntangibleAssetsLineItems" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="acgl_IntangibleAssetsIncludingGoodwillAcquiredDuringthePeriod" abstract="false" name="IntangibleAssetsIncludingGoodwillAcquiredDuringthePeriod" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="acgl_IntangibleAssetsIncludingGoodwillForeignCurrencyTranslationAndOtherAdjustments" abstract="false" name="IntangibleAssetsIncludingGoodwillForeignCurrencyTranslationAndOtherAdjustments" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="acgl_IntangibleAssetsIncludingGoodwillGrossToNetAbstract" abstract="true" name="IntangibleAssetsIncludingGoodwillGrossToNetAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="acgl_IntangibleAssetsLiabilitiesandGoodwillGross" abstract="false" name="IntangibleAssetsLiabilitiesandGoodwillGross" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="acgl_IntangibleAssetsIncludingGoodwillAccumulatedForeignCurrencyAndOtherAdjustments" abstract="false" name="IntangibleAssetsIncludingGoodwillAccumulatedForeignCurrencyAndOtherAdjustments" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="acgl_IntangibleLiabilityMember" abstract="true" name="IntangibleLiabilityMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acgl_SyndicateCapacityMember" abstract="true" name="SyndicateCapacityMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acgl_AuthorizedShareRepurchaseProgramMember" abstract="true" name="AuthorizedShareRepurchaseProgramMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acgl_TreasuryStockSharesAcquiredCumulativeSinceInception" abstract="false" name="TreasuryStockSharesAcquiredCumulativeSinceInception" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:sharesItemType"/>
  <xs:element id="acgl_TreasuryStockValueAcquiredCumulativeSinceInception" abstract="false" name="TreasuryStockValueAcquiredCumulativeSinceInception" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="acgl_ProportionateInterestofPreferenceSharesPerDepositaryShare" abstract="false" name="ProportionateInterestofPreferenceSharesPerDepositaryShare" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="acgl_A2022LongTermIncentiveAndShareAwardPlanMember" abstract="true" name="A2022LongTermIncentiveAndShareAwardPlanMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acgl_TwoThousandEighteenLongTermIncentiveandShareAwardPlanMember" abstract="true" name="TwoThousandEighteenLongTermIncentiveandShareAwardPlanMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acgl_EmployeeSharePurchasePlanMember" abstract="true" name="EmployeeSharePurchasePlanMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acgl_PremiumPricedStockOptionAwardsMember" abstract="true" name="PremiumPricedStockOptionAwardsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acgl_ShareBasedPaymentAwardOptionsExercisePriceToMarketPriceMultiplierAtGrantDate" abstract="false" name="ShareBasedPaymentAwardOptionsExercisePriceToMarketPriceMultiplierAtGrantDate" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="acgl_PerformanceAwardsSharesMember" abstract="true" name="PerformanceAwardsSharesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acgl_PerformanceAwardsUnitsMember" abstract="true" name="PerformanceAwardsUnitsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acgl_ShareBasedCompensationPerformanceAdjustment" abstract="false" name="ShareBasedCompensationPerformanceAdjustment" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:sharesItemType"/>
  <xs:element id="acgl_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsPerformanceAdjustmentWeightedAverageGrantDateFairValue" abstract="false" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsPerformanceAdjustmentWeightedAverageGrantDateFairValue" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:perShareItemType"/>
  <xs:element id="acgl_ShareBasedCompensationPerformanceAwardsPayoutPercentage" abstract="false" name="ShareBasedCompensationPerformanceAwardsPayoutPercentage" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="acgl_TimeVestedRestrictedSharesMember" abstract="true" name="TimeVestedRestrictedSharesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acgl_ArchReUSMember" abstract="true" name="ArchReUSMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acgl_ArchGroupReinsuranceLtdMember" abstract="true" name="ArchGroupReinsuranceLtdMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acgl_NorthCarolinaOrWisconsinMember" abstract="true" name="NorthCarolinaOrWisconsinMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="acgl_StatutoryAccountingPracticesDividendsPermittedPercentageOfStatutoryCapitalAndSurplus" abstract="false" name="StatutoryAccountingPracticesDividendsPermittedPercentageOfStatutoryCapitalAndSurplus" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="acgl_StatutoryCapitalAndSurplusNoticePeriodRequiredForDividends" abstract="false" name="StatutoryCapitalAndSurplusNoticePeriodRequiredForDividends" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="acgl_NumberOfSubsidiaries" abstract="false" name="NumberOfSubsidiaries" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="acgl_StatutoryAccountingContingencyLossReservePercentageOfNetEarnedPremiums" abstract="false" name="StatutoryAccountingContingencyLossReservePercentageOfNetEarnedPremiums" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="acgl_WithdrawalRestrictionPeriod" abstract="false" name="WithdrawalRestrictionPeriod" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="acgl_StatutoryAccountingContingencyLossReservePercentageOfNetEarnedPremiumsWithPriorApproval" abstract="false" name="StatutoryAccountingContingencyLossReservePercentageOfNetEarnedPremiumsWithPriorApproval" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="acgl_MaximumRiskToCapitalRatio" abstract="false" name="MaximumRiskToCapitalRatio" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="acgl_InvestmentInSubsidiaries" abstract="false" name="InvestmentInSubsidiaries" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="acgl_DueToSubsidiariesAndAffiliates" abstract="false" name="DueToSubsidiariesAndAffiliates" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="acgl_BalanceSheetAdditionalInformationAbstract" abstract="true" name="BalanceSheetAdditionalInformationAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="acgl_IncomeLossBeforeIncomeTaxesAndEquityInNetIncomeOfOperatingAffiliates" abstract="false" name="IncomeLossBeforeIncomeTaxesAndEquityInNetIncomeOfOperatingAffiliates" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="acgl_IncomeLossNetOfIncomeTaxesAndBeforeEquityInNetIncomeOfSubsidiaries" abstract="false" name="IncomeLossNetOfIncomeTaxesAndBeforeEquityInNetIncomeOfSubsidiaries" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="acgl_PremiumsWrittenPercentageAssumedToNet" abstract="false" name="PremiumsWrittenPercentageAssumedToNet" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
</xs:schema>
