Calculation of Easter in the Celtic Church?

Question

OK, so one of the big arguments between the Roman and Celtic churches back in the 7th century, was the calculation of Easter. The Roman church used the Peter/Paul method - first Sunday after the first full moon after the Vernal Equinox. Anyone out there know how the Celtic church calculated it? Been looking for years, never been able to find out. (Some think they used the Johannine calculation - though no one seems to know what this was either - or at least no one I've come across).

Thanks for the first long answer. I'm already very familiar with the Synod of Whitby - that doesn't help at all. The rest was interesting reading, but doesn't actually answer the question - except to suggest that perhaps no one actually knows - something that's got lost in time?

For whoever loves louis - the catholic Church is a church which is open to all and encompasses all people (catholicism is a word in its own right, not necessarily associated with religion). The term 'Church' when used in this context is really a reference to the faith rather than an institution or building. The Roman Catholic Church is one denomination of Christianity. It was not the earliest, and has never been the only denomination. It really started to form into what we see today in the 4th century. The word 'catholic' has come to be seen only in the context of the church these days, but it is actually descriptive word which could be used in other contexts.

Answer 1

Check out anything on the Synod of Whitby, which was when the changes were imposed.

This from dear old Wikipedia,

"A distinguishing mark of Celtic Christianity was its distinct conservatism, even archaism.[10] One example is their method of calculating Easter. Calculating the proper date of Easter was (and is) a complicated process involving a lunisolar calendar. Various tables were produced in antiquity that attempted to calculate Easter for a series of years. Insular Christianity used a calculation table (Celtic-84) that was similar to one approved by St. Jerome. However, by the sixth and seventh centuries it had become obsolete and had been replaced by those of Victorius of Aquitaine and, more accurately, those of Dionysius Exiguus. As the Celtic world established renewed contact with the Continent it became aware of the divergence; most groups, like the southern Irish, accepted the updated tables with relatively little difficulty, with the notable exception of monks from the monastery of Iona and its many satellite institutions.[11] For example, the southern Irish accepted the common Easter calculation at the Synod of Mag Léne around 630, as did the northern Irish at the Council of Birr around 697, and Northumbria with the Synod of Whitby in 664. Nonetheless, in 716 Iona converted its practice."

.......and,

"One of the main differences between the two traditions, and hence a source of controversy, was the proper calculation of Easter. Early Christians had probably originally celebrated Easter concurrent with the Jewish Passover (see Passover, Christian holiday), which was held on the fourteenth day of the first lunar month of the Jewish year, called nisan, the day of the crucifixion according to John 19:14. However, it came to be considered that Easter should be held on a Sunday, the day of the resurrection, and the First Council of Nicaea in 325 fixed the precise date for celebrating Easter so that all Christian churches in all regions should celebrate the principal festival of the Church on the same day[5], according to Philip Schaff's History of the Christian Church, volume 3, section 79, The Time of the Easter Festival: "The leading motive for this regulation was opposition to Judaism, which had dishonored the passover by the crucifixion of the Lord." However, calculating the proper date was a complex process (involving a lunisolar calendar), and different calculation tables developed which resulted in different dates for the celebration of Easter. By the 660s, Ionan adherents were still using calculation tables that had been regarded as in error by Rome (ultimately in favor of the tables of Dionysius Exiguus). The Ionan tables not only often resulted in a different date for the celebration of Easter, but they also allowed Easter to be celebrated on nisan xiv if that were a Sunday, whereas Roman custom would have Easter moved to a different week in such a year (see ecclesiastical computus). The Ionan Easter had already resulted in conflict in Gaul, in the early seventh century, between Frankish monasteries and Ionan monasteries (the latter had been founded there by the Ionan abbot St. Columbanus), and the Ionan tables had been rejected. Likewise, synods in southern Ireland, in the 630s, had also considered the matter and accepted the Easter calculation according to the custom of Rome."

**EDIT**
Sorry this didn't answer your question. You obviously need to get hold of a copy of the Ionan tables that the Celtic Church used to calculate Easter.
You could try "Bede, Historiam Ecclesiasticam Gentis Angelorum" or "Cubitt, Catherine, Anglo-Saxon Church Councils c. 650-850 (London: Leicester University Press, 1995) ".
Alternatively, a call to the British Museum may do the trick.
Good luck.

Answer 2

There were many Celtic religions/cults. Most Celtic religions were based around worshipping nature and witchcraft. Some Celtic groups half adopted Chrisitianty, where they would mix in Christian theology with Pagan theology. I have a feeling the Celtic Church was based upon that.

Answer 3

calculating the date of Easter is complicated process involving a lunisolar calendar. Various tables were produced in antiquity that attempted to calculate Easter for a series of years

Answer 4

hi sorry i don't know the answer to your question but it has prompted a question of my own that i thought you would know, what you are asking is that the difference between catholics and roman catholics as i have always wondered the difference thanks x