So this week we are coming up on Easter, which is the biggest holiday in the medieval Christian calendar aside from Christmas! Since Easter constantly confuses with its jumping dates, we are going to look at the medieval "easter controversy" and this holiday's long, strange, and convoluted history.
In order to understand why we celebrate Easter on a different Sunday each year, we first have to understand the medieval concept of computus. Computus generally refers to the computation of Easter Sunday, but in the later Middle Ages the term eventually referred to any time reckoning or time computation. This shift is more noticeable in Bede's De Temporum Ratione (On the Reckoning of Time). Bede also helped establish the BC/AD system, which was established first by Dionysius Exiguus in about 500 AD. When we discuss computus below, however, it primarily has to do with the Easter reckoning. While our modern world generally has an established calendar, folk in the middle ages didn’t have a singular way of reckoning time.
There are a few obvious ways the medievals could reckon time - by the seasons, sun cycles (day/night), and moon cycles (which eventually became months). The Celtic calendar was largely based on this system, with holidays focused around change of seasons and moon cycles.
The Julian calendar another popular calendar, since it established kalens, which are essentially months, and a yearly cycle. Julius Caesar established this in 46 BC, based on the earlier Roman calendar. The Julian calendar was used by most of continental Europe in the early and later Middle Ages since it had been in use for so long under Roman rule.
The Julian system was also useful because it was a solar calendar, in which one could calculate days of the week and month. Days in the month could change year to year, and leap years would also be accounted for. While the Julian calendar looks closer to our modern monthly calendar, the medievals counted the days differently.
Rather than counting the days of the kalens (the month), medievals would tick the days before or after a few major days - like the nones (either the 7th or the 9th day of the month) and the ides (the 15th, or eight days after the nones). If a festival fell five days before the ides, the date would be written out V ID - representing "five days before ides." Dates later in the month would include dates written like III KL, or "there days before the kalens" and would represent the third day from the end of the month.
Regnal years were another popular way of reckoning time. This calendar used a year system but counted how many years into a reign one lived. This system was limited in scope, and can make it difficult to date certain papers if we don’t know who was king at the time of writing. Sometimes, a regnal year would be written with the Julian year, which is immensely useful for medievalists to correlate other documents and events which may only have one "timestamp" or date.
Another way to calculate time was AM or anno mundi - the year of the world. This was based on the year of biblical creation, which scribes and scholars would attempt to figure out based on either the Hebrew calendar (which is still used by some orthodox Jewish communities) or by hand-calculating the years and lifespans of people in the Bible. Interestingly, issues of time calculation also increased fears about the end of the world, especially if using AM timeframes- the 6,000th year of creation (commonly associated with the apocalypse) could either have been 500 AD or 800 AD, depending on the calculation, and 1000 was also seen as a possible year. For more on this, see article by James Palmer on Calculating the Apocalypse. All of these ways of reckoning time had political consequences and stances, some of which also affected the Easter controversy.
So, given all this background into time reckoning - what does this have to do with Easter?
Easter’s modern name is actually a shortening of the Old English “Eosturmonath” or “the month of Eostre”. Bede recalls how this month was named after the pagan goddess of fertility, but the holiday itself was still referred to as Paschal. Paschal itself is derived from Pentecost and the Jewish Passover festival. The term itself is Greek, first from Aramaic and Hebrew cognates of the Passover, which celebrates the original Passover of the angel in Egypt during Israel's captivity. In Christian theology, Pascal derives from Pentecost and refers to the descending of the Holy Spirit on the disciples after Christ’s resurrection and ascension.
Easter itself was a “movable feast” which was calculated originally on the Jewish lunisolar calendar, but was then determined to be independent by the Council of Nicaea in 325 to avoid the Jewish Passover holiday. Notably, the council never specified Easter had to fall on a Sunday, but the tradition was well ingrained by that point. An established Easter calculation had been set down at that time, but because Easter had been based on the lunisolar calendar of the Jews, it did not match the Julian calendar years.
Soon, the calculation of Easter became the "Easter controversy" because no one knew when Easter Sunday should fall. According to Bede, the “lawful” Easter is supposed to be “the Sunday following the full moon which falls on or after the equinox.” However, this depends again upon which calendar you use, and how the equinox naturally varies - the Nicean council determined it was on March 21 regardless of the actual astronomical event. The Jewish Passover calculation and the Julian calendar didn't match, and the church refused to have Easter on the same day as Passover, even if it should be. Since the lunar year and the solar year did not match, and now the ecclesiastical equinox was on a singular date, the day and month at which Easter Sunday fell varied, and therefore had to be calculated in advance, especially for churches and communities that did not have a scribe or priest who could calculate these tables themselves.
To add more complexity, Dionysius established the BC/AD system (known as the Christian era) through an adapted 84-year cycle Easter table to even out the days between the lunar and solar calendars. This contrasted strongly with the Irish and British calculations of Easter, which were first based on an AM calendar and which eventually made the full moons earlier and earlier. Additionally, as Bede noticed, the calculation of the tables was in error itself; when it was established, it worked well, but after about two centuries, it failed to account for the reality of time, the equinox, and the calendar.
The remaining controversy was based on which Sunday it needed to fall, and whether it should be calculated based on astronomy, versus tradition. In some cases, Easter tables were established long in advance, so that local communities could just pick out that Sunday without worry. In order to make these dates and feast dates “fit” however, sometimes scribes would fudge the numbers. Alternatively, scribes could make errors in copying these tables and charts from their model text, so that a scribe might misunderstand the "golden day" (that is, the day of Easter Sunday) as "two" when it should have been a "five." This error was often due to how the strokes of the number looked, as a II looked very close to a V in some styles.
All of these errors piled over the centuries led to increasingly wrong Easter and feast computations. Two communities might be celebrating Easter a few weeks apart. Returning to fears of the apocalypse when doing computus, many folk thought that celebrating Easter on the wrong day - a "dark Easter" - would result in apocalyptic events or bad fortune. A Dark Easter could result in floods, fire, or other disaster that could ruin a farmer's crops or devastate a town. The celebration of Pascal was not simply a semantics issue, but an issue of life and death which would also impact the everyday lives of those celebrating.
Regardless of how you celebrate Easter, put your medieval manuscript reading and computus skills to the test with a few of the manuscripts we discussed in this episode!
Thanks for joining us in this week's episode of The Maniculum Podcast. Looking for more? Check out our Master List series for the full collection of segments at the end of our show, and for more gaming and world building ideas, check out The Gaming Table section of our blog, Marginalia!
Bernhardt-House, Philip A. "Queer Conceptions and Calculations: Niall Frossach and the Easter Controversy." The Canadian Journal of Irish Studies, Vol. 39, No. 1, 2015, pp. 186-205.
Bisagni, Jacopo, and Immo Warntjes. “Latin and Old Irish in the Munich Computus: A Reassessment and Further Evidence.” Ériu, vol. 57, 2007, pp. 1–33. Link.
Edson, Evelyn. “World Maps and Easter Tables: Medieval Maps in Context.” Imago Mundi, vol. 48, 1996, pp. 25–42. Link.
Palmer, James. “Calculating Time and the End of Time in the Carolingian World, C.740—820.” The English Historical Review, vol. 126, no. 523, 2011, pp. 1307–1331. Link.
psarando. Shire Reckoning: A visualization of the calendars described in J.R.R. Tolkien's The Lord of the Rings Appendix D. Link.
Warntjes, Immo. “The Munich Computus and the 84 (14)-Year Easter Reckoning.” Proceedings of the Royal Irish Academy. Section C: Archaeology, Celtic Studies, History, Linguistics, Literature, vol. 107C, 2007, pp. 31–85. Link.
Willis, Faith. "What a Medieval Diagram Shows: A Case Study of 'Computus'." Studies in Iconography, vol. 36, 2015, pp. 1–40. Link.
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