EventheyearfollowingtheCouncilofNicea--thatis,in326--aswellasintheyears330,333,340,341,343,theLatinscelebratedEasteronadifferentdayfromtheAlexandrians.Inordertoputanendtothismisunderstanding,theSynodofSardicain343,aswelearnfromthenewlydiscoveredfestivallettersofS.Athanasius,tookupagainthequestionofEaster,andbroughtthetwoparties(AlexandriansandRomans)toregulate,bymeansofmutualconcessions,acommondayforEasterforthenextfiftyyears.Thiscompromise,afterafewyears,wasnotobserved.ThetroublesexcitedbytheArianheresy,andthedivisionwhichitcausedbetweentheEastandtheWest,preventedthedecreeofSardicafrombeingputintoexecution;thereforetheEmperorTheodosiustheGreat,afterthere-establishmentofpeaceintheChurch,foundhimselfobligedtotakefreshstepsforobtainingacompleteuniformityinthemannerofcelebratingEaster.In387,theRomanshavingkeptEasteronMarch21st,theAlexandriansdidnotdosoforfiveweekslater--thatistosay,tillApril25th--becausewiththeAlexandrianstheequinoxwasnottillMarch21st.TheEmperorTheodosiustheGreatthenaskedTheophilus,BishopofAlexandriaforanexplanationofthedifference.ThebishoprespondedtotheEmperor'sdesire,anddrewupachronologicaltableoftheEasterfestivals,basedupontheprinciplesacknowledgedbytheChurchofAlexandria.Unfortunately,wenowpossessonlytheprologueofhiswork.
UponaninvitationfromRome,S.AmbrosealsomentionedtheperiodofthissameEasterin387,inhislettertothebishopsofAEmilia,andhesideswiththeAlexandriancomputation.CyrilofAlexandriaabridgedthepaschaltableofhisuncleTheophilus,andfixedthetimefortheninety-fivefollowingEasters--thatis,from436to531afterChrist.BesidesthisCyrilshowed,inalettertothePope,whatwasdefectiveintheLatincalculation;andthisdemonstrationwastakenupagain,sometimeafter,byorderoftheEmperor,byPaschasinus,BishopofLilybaeumandProteriusofAlexandria,inaletterwrittenbythemtoPopeLeoI.Inconsequenceofthesecommunications,PopeLeooftengavethepreferencetotheAlexandriancomputation,insteadofthatoftheChurchofRome.Atthesametimealsowasgenerallyestablished,theopinionsolittleentertainedbytheancientauthoritiesoftheChurch--onemightevensay,sostronglyincontradictiontotheirteaching--thatChristpartookofthepassoveronthe14thNisan,thathediedonthe15th(notonthe14th,astheancientsconsidered),thathelayinthegraveonthe16th,androseagainonthe17th.Intheletterwehavejustmentioned,ProteriusofAlexandriaopenlyadmittedallthesedifferentpoints.
Someyearsafterwards,in457,VictorofAquitane,byorderoftheRomanArchdeaconHilary,endeavouredtomaketheRomanandtheAlexandriancalculationsagreetogether.IthasbeenconjecturedthatsubsequentlyHilary,whenPope,broughtVictor'scalculationintouse,in456--thatis,atthetimewhenthecycleofeighty-fouryearscametoanend.Inthelattercyclethenewmoonsweremarkedmoreaccurately,andthechiefdifferencesexistingbetweentheLatinandGreekcalculationsdisappeared;sothattheEasteroftheLatinsgenerallycoincidedwiththatofAlexandria,orwasonlyaverylittleremovedfromit.IncaseswhentheidfellonaSaturday,VictordidnotwishtodecidewhetherEastershouldbecelebratedthenextday,astheAlexandriansdid,orshouldbepostponedforaweek.Heindicatesbothdatesinhistable,andleavesthePopetodecidewhatwastobedoneineachseparatecase.EvenafterVictor'scalculations,therestillremainedgreatdifferencesinthemanneroffixingthecelebrationofEaster;anditwasDionysiustheLesswhofirstcompletelyovercamethem,bygivingtotheLatinsapaschaltablehavingasitsbasisthecycleofnineteenyears.ThiscycleperfectlycorrespondedtothatofAlexandria,andthusestablishedthatharmonywhichhadbeensolongsoughtinvain.Heshowedtheadvantagesofhiscalculationsostrongly,thatitwasadmittedbyRomeandbythewholeofItaly;whilstalmostthewholeofGaulremainedfaithfultoVictor'scanon,andGreatBritainstillheldthe'cycleofeighty-fouryears,alittleimprovedbySulpiciusSeverus.WhentheHeptarchywasevangelizedbytheRomanmissionaries,thenewconvertsacceptedthecalculationofDionysius,whilsttheancientChurchesofWalesheldfasttheiroldtradition.Fromthisarosethewell-knownBritishdissensionsaboutthecelebrationofEaster,whichweretransplantedbyColumbanintoGaul.In729,themajorityoftheancientBritishChurchesacceptedthecycleofnineteenyears.IthadbeforebeenintroducedintoSpain,immediatelyaftertheconversionofReccared.Finally,underCharlestheGreat,thecycleofnineteenyearstriumphedoverallopposition;andthusthewholeofChristendomwasunited,fortheQuartodecimanshadgraduallydisappeared.(1)
selectedfromHenryR.Percival,ed.,TheSevenEcumenicalCouncilsoftheUndividedChurch,VolXIVofNiceneandPostNiceneFathers,2ndseries,edd.PhilipSchaffandHenryWace,(repr.Edinburgh:T&TClark;GrandRapidsMI:Wm.B.Eerdmans,1988),pp.54-56