Complex sentence: At some time between 1144 and 1146 Oxford refused to live with his wife, Beatrice, and her father, the Constable of Bourbourg, arranged a divorce with the Earl's consent, after which Oxford ceased to be Count of Guînes.
Split into simpler sentences: At some time between 1144 and 1146 Oxford refused to live with his wife, Beatrice. Her father, the Constable of Bourbourg, arranged a divorce with the Earl's consent, after which Oxford ceased to be Count of Guînes.