Excerpt: "Determining the correct date for the celebration of Easter involves important theological and practical considerations. Since there was no universal agreement about the manner in which these considerations should be addressed it is not surprising that the dating ofEaster became contentious, causing controversy and conflict in the church for centuries. When Columbanus (d. 615) arrived on the Continent in the late sixth century, he brought with him an older system for dating Easter that was different from the one in use in Rome or the Merovingian churches. Within a few years, the two sides were debating questions of authority and interpretation in an attempt to defeat one another's position or reach a resolution. The controversy between Columbanus and the Merovingian episcopacy reveals in microcosm many of the arguments that would be used throughout the process by which the Irish churches eventually abandoned their traditional method of calculating Easter in favour of the Roman practice."
Corning, Caitlin, "Columbanus and the Easter Controversy: Theological, Social and Political Contexts (Chapter 6 in The Irish in Early Medieval Europe)" (2016). Faculty Publications - Department of History, Politics, and International Studies. 92.