Complex sentence: After the Norman conquest of England in 1066 Deddington was owned by Odo, Bishop of Bayeux, who was William the Conqueror's step-brother and built Deddington Castle in what is now the east of the town.
Split into simpler sentences: After the Norman conquest of England in 1066, William the Conqueror's step-brother Odo, Bishop of Bayeux, held the manor of Deddington. Odo had Deddington Castle built in what is now the east of the town.