Complex sentence: The author is generally supposed to have come from the village of Oxnead, which lies about ten miles from the abbey, which is supported by the fact that a number of monks at the abbey were given the name of their village as an appellation.
Split into simpler sentences: The author is generally supposed to have come from the village of Oxnead, which lies about ten miles from the abbey. This supposition is supported by the fact that a number of monks at the abbey were given the name of their village as an appellation.