In order to celebrate Good Friday, we are exploring the fascinating origins of the Christian festival of Easter. The following is an extract from The History of Time: A Very Short Introduction by Leofranc Holford-Strevens.
Easter, commemorating the Resurrection of Jesus Christ, is historically the most important of all Christian festivals, even though in some Western countries it has largely lost the religious significance it retains amongst the Orthodox; nevertheless it merits discussion in a broader context not only because it is often a public as well as a religious holiday, or indeed because even Christians may be baffled by its apparently capricious incidence, but because the history of its calculation illustrates many complexities of time-reckoning.
The origin of Easter is the Jewish Passover, known in Hebrew as pesaḥ but in Aramaic, the normal spoken language of Jews in Roman Palestine, as pasḥā, which in Greek became páscha. (From this comes our adjective ‘Paschal’; the name ‘Easter’ is transferred from a Germanic festival.) Passover, in biblical times, was the slaughter of the Paschal lamb on 14 Nisan; it was eaten at nightfall, the beginning of the 15th by Jewish reckoning, and therefore of the seven-day Feast of Unleavened Bread.
According to St John’s Gospel, the Crucifixion took place in the daytime of 14 Nisan; this date seems more plausible than the 15th offered by the other three gospels, since that day would have been profaned by the proceedings. It was therefore natural for early Christians, many of them still Jews, to commemorate the Crucifixion on 14 Nisan, making Jesus the Lamb of God sacrificed to redeem humanity; the association was all the easier because in Greek páscha suggested the verb páschein, ‘to suffer’. Even after Christianity had become a largely Gentile religion, the practice continued in Asia Minor, where the authority of St John was claimed for it, long after most other Christians had abandoned it. Such persistence was eventually classed as a heresy, known as Quartodecimanism.
However, since Jesus had risen on Sunday, that day was observed as a weekly feast day; in time it became normal, rather than to keep the anniversary of the Crucifixion, to celebrate that of the Resurrection, in the eastern provinces on the Sunday after Passover, elsewhere on the Sunday after a date found by independent calculation, both to avoid dependence on the Jews and because the increasingly widespread custom of fasting before it required knowing the date in advance. This entailed finding the 14th day of the first lunar month, called simply tessareskaidekátē, ‘fourteenth’, in Greek, but in Latin luna quartadecima, literally the ‘fourteenth moon’, abbreviated below as luna XIV. Once luna XIV had been found, the next Sunday had to be identified. The method of making these calculations is known as computus.
From the 3rd century onwards, most churches agreed that Easter should be the Sunday after luna XIV; but that was only the beginning. Two questions of principle remained: when the first lunar month began, and whether, should luna XIV be a Sunday, to observe Easter on that day or the following Sunday in order to keep apart from the Jews, who had not yet adopted a rule by which 14 Nisan could never be a Sunday. The latter became the more widespread practice; at Rome the conception of 14 Nisan as the first Good Friday caused Easter to be postponed even when luna XIV fell on Saturday, so that the feast was never earlier than the 16th lune or day of the lunar month (luna XVI), on which the Resurrection had taken place, and might be as late as the 22nd (luna XXII).
On the other hand, it was essential that it should not fall after 21 April, the day of the Parilia, celebrating Romulus’ foundation of the City, lest Christians, forced to fast on a civic feast, should be subject to hostility or temptation. Both the lunar limit of the 16th to 22nd lunes, and the lower solar limit of 21 April, are found in a calendar with base-year 222 inscribed in Greek on a stone chair now standing at the foot of the stairs in the Vatican Library.
In this calendar Easter may fall as early as 18 March; but Christians began to complain that Jews were no longer following their own rule that Passover should not precede the vernal equinox. This allegation was due partly to a misunderstanding of the Jewish rules, but partly to demonstrable variety in practice between one Jewish community and another. But if the Jewish Pascha ought not to precede the vernal equinox, it followed that the Christian Pascha ought not to do so either; by the 4th century the Church at Rome, where the date of the equinox was still taken to be 25 March, seems to have taken that view, though it could not be sustained in practice. At Alexandria the more rigorous principle was adopted that luna XIV itself, the proper date of Passover, must not precede the equinox, which was (more accurately) equated with 25 Phamenoth = 21 March; on the other hand, there was no lower limit, since 21 April (locally 26 Pharmouthi) was of no significance.
Featured image credit: Gordale Beck, by David Benbennick, CC BY-SA 3.0 via Wikimedia Commons