The Synod of Whitby was a seventh century Northumbrian synod where King Oswiu of Northumbria ruled that his kingdom would calculate Easter and observe the monastic tonsure according to the customs of Rome, rather than the customs practised by Iona and its satellite institutions. The synod was summoned in 664 at Saint Hilda's double monastery of Streonshalh (Streanæshalch), later called Whitby Abbey.
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