Complex sentence: He spent time as a hermit at Cailly and at Rouen; he founded the abbey of La Croix-Saint-Qu'en around 690, and served as its first abbot.
Split into simpler sentences: He spent time as a hermit at Cailly and at Rouen. He founded the abbey of La Croix-Saint-Qu'en around 690, and served as its first abbot.