Complex sentence: Hilary spent many years struggling with Battle Abbey over his attempts to inspect the abbey, and he also clashed with Thomas Becket, then chancellor to King Henry II of England, later Archbishop of Canterbury.
Split into simpler sentences: Hilary spent many years struggling with Battle Abbey over his attempts to inspect the abbey. During the course of the conflict, Hilary clashed with Thomas Becket, then chancellor to King Henry II of England, later Archbishop of Canterbury.