The Hiberno-Scottish mission was a series of expeditions in the 6th and 7th centuries by Gaelic missionaries originating from Ireland that spread Celtic Christianity in Scotland, Wales, England and Merovingian France. Catholic Christianity spread first within Ireland. Since the 8th and 9th centuries, these early missions were called 'Celtic Christianity'.
There is dispute over the relationship of the Hiberno-Scottish mission to Catholic Christianity. Catholic sources claim it functioned under the authority of the Holy See,[1] while Protestant historians highlight conflicts between Celtic and Roman clergy.[2] There is agreement that the mission was not strictly coordinated.[3] As a whole, Celtic-speaking areas were part of Latin Christendom at a time when there was significant regional variation of liturgy and structure, but a general collective veneration of the Papacy was no less intense in Celtic-speaking areas.[4]
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