Early Christians in Britain and Ireland also used an 84-year cycle. From the 5th century onward this cycle set its equinox to 25 March and fixed Easter to the Sunday falling in the 14th to the 20th of the lunar month inclusive. This 84-year cycle was replaced by the Alexandrian method in the course of the 7th and 8th centuries. Churches in western continental Europe used a late Roman method until the late 8th century during the reign of Charlemagne, when they finally adopted the Alexandrian method. Since 1582, when the Catholic Church adopted the Gregorian calendar while the Eastern Orthodox and most Oriental Orthodox Churches retained the Julian calendar, the date on which Easter is celebrated has again differed.