Complex sentence: William De Ow was a cousin of William the Conqueror and during the Domesday Book he was owner of Stonehouse Manor, a grade II listed manor in the Cotswolds town of Stonehouse in Gloucestershire.
Split into simpler sentences: William De Ow was a cousin of William the Conqueror. At the time of the Domesday Book he was owner of Stonehouse Manor, a grade II listed manor in the Cotswolds town of Stonehouse in Gloucestershire.