If we suppose that a table of Paschal computation was brought by Patrick to Ireland in the first half of the fifth century, it is not probable that he would have introduced any other than the _supputatio Romana_. This inference does not depend on the view which we adopt as to Patrick’s relations to the Church of Rome. It depends upon his connexion with the Gallic Church. There is no evidence, so far as I can discover,[423] that the Gallic Church did not agree with the Roman in the fourth and fifth centuries as to the Paschal limits. We should have to suppose that Patrick rejected both the system prevailing in western Europe, and the Alexandrine system, in favour of the older usage prevailing in his native country, Britain; and this, in view of the circumstances of his career, seems extremely unlikely.[424] The evidence, in my opinion, suggests rather a different conclusion. It suggests that the Paschal system which prevailed in Britain in the fourth century and survived to the seventh had been introduced from Britain into Ireland, and taken root among the Christian communities there, _before the arrival of Patrick_. This is what we should expect. It is in accordance with the hypothesis of the British origin of pre-Patrician Christianity in Ireland. It is easy to comprehend that Patrick, though accustomed to the _supputatio Romana_, acquiesced in the continuance of the other system or was unable to change it. It would be not at all easy to comprehend that, if he had found Ireland a _tabula rasa_ ready to receive any Paschal calculation that he might choose to inscribe, he should not have introduced the system generally received in the Western Church unless it were the system generally received in the Eastern Church. The Paschal evidence appears to be another proof of pre-Patrician Christianity in Ireland. But if Patrick acquiesced in the continuance of the old system and did not make the fixing of the Paschal feast a crucial question in Ireland, it does not follow that he adopted it himself or may not have made some attempt to introduce another canon. There is no _a priori_ objection to the possibility that, while the old method continued in the old-established communities, he may have sanctioned a different table in the new communities which he founded. This brings us to the consideration of an important piece of evidence contained in the letter of Cummian addressed to Segéne, Abbot of Hy (probably in 632 A.D.[425]), arguing for the Roman Easter. Cummian states definitely that the Pasch of Patrick differed from the Pasch of the Irish and Britons. He describes the cycle used by Patrick thus:[426] illum [cyclum] quem sanctus Patricius, papa noster, tulit et facit (_leg._ fecit), in quo luna a xiv usque in xxi regulariter et aequinoctium a xii Kl. April obseruatur.