could sometimes lead to situations where no Easter date would be accept-
able.^124 The limits of Easter were different in Alexandria, at least according to
the Alexandrian cycle (whenever it was instituted), withluna XV–XXIand 22
March–25 April (in the Alexandrian calendar 26 Phamenoth–30 Pharmuthi).
The upper solar limit, 22 March, derives from the rule of the equinox, whereby
luna XIVcannot occur before the equinox (which is assumed, in the Alexan-
drian cycle, to be on 21 March); 22 March, onluna XV, is thus the earliest
Easter can occur.^125 The rule of the equinox appears to have been advocated by
Peter of Alexandria in the 310s, and thus may have been followed some time
already before Nicaea.^126
These different limits, which are likely to have been followed in Alexandria
and Rome already at the time of the Council of Nicaea, as well as the use of
different cycles producing often different dates ofluna XIV, would have led
not infrequently to disagreement between Rome and Alexandria on the date of
Easter. It is most likely because of these differences, and because of the
impossibility of ignoring either Rome or Alexandria or making one surrender
to the other, that no concrete decision was reached at Nicaea on the computa-
tion of the date of Easter.^127 In contrast to the Council of Arles, which was
attended only by western bishops submissive to the bishop of Rome and
willing to accept the latter’s dates of Easter, the Council of Nicaea encom-
passed too much diversity, from East and fromWest, for any such agreement
to be reached. This explains why in his post-synodal letter, Constantine
cautiously avoided any reference to Easter cycles or rules. For political reasons,
it was more expedient to be content with a single, relatively simple common
cause: that of no longer following the Jews.^128
Nevertheless, Constantine’s directive at Nicaea that the same date of Easter
be observed by all, which in subsequent decades the pro-Nicene bishops of
Rome and Alexandria saw the value in obeying, led the latter to compromise
with each other and adopt, in most years, the same dates of Easter. From 328
CE, Athanasius of Alexandria seems to have been the main promoter of
evidence in support of this explanation, see Lejbowicz (2006) 47, (2008) 297 n. 91 = (2010) 28
n. 91, and Mosshammer (2008) 169–70.
(^124) As in 387CE: see Stern (2001) 144.
(^125) The generous lower limit, 25 April, is perhaps not so much a rule as the result of how
the Alexandrian cycle happens to be constructed. The lunar limits ofXV–XXIconform to the
chronology of the Gospel of John, according to which the Friday of the Crucifixion was the eve of
Passover orluna XIII, hence the Resurrection on Sundayluna XV(see above, n. 123).
(^126) On the letter of Peter of Alexandria to Tricentius, see Stern (2001) 66–7, 72–4.
(^127) See previous section and n. 96. The sole reference to Easter in the synodal letter cited by
SocratesHE1. 9 (partially cited above, n. 107) betrays the tension between Rome and Alexandria
at the Council of Nicaea, as argued by Lejbowicz (2006) 39–42.
(^128) See above, n. 112. Lejbowicz (2006) 49–50 also suggests that the bishops assembled at
Nicaea—not to mention Constantine himself [SS]—would not have known enough about
computus to engage in any useful debate on the subject.
406 Calendars in Antiquity