To keep Easter together during the Biblical festival of Passover was the shared dream of all the earliest Christian churches. But everyone seemed to have questions about how and when to celebrate the most important feast of the year, and no one seemed to have answers.
IN 325, bishops from around the world gathered at Nicaea near Constantinople, and one of the topics discussed was Easter. Christ died and rose again at Passover, the week-long Jewish festival at the first full moon of Spring, and Christians had always wanted to celebrate Easter at that time each year.
But no astronomer could determine the northern vernal equinox or a full moon with precision, and Jewish calendars were an unsatisfactory clutter of leaps and intercalary months.
Most churches kept Easter on a Sunday, the historical day of resurrection – if that was the first day of Passover, out of respect for the crucifixion they waited another week – but not everyone thought this important.*
The Nicene Council confirmed the tradition of a Sunday in Passover, and forbade routinely pegging the date to whatever the synagogue did; but nothing more was said about determining Passover itself. With astronomy in its infancy, and competing mathematical solutions already circulating, there was still plenty of work ahead.
* Passover may begin on any day of the week. The fact that Jesus was crucified on a Friday meant that his resurrection ‘on the third day’ (counting the day of crucifixion as the first) came sometime in the very early hours of Sunday, known even now in Greek as “Kiriaki”, the Lord’s Day, or in Russian as “Voskresen’ye”, Day of Resurrection.