Complex sentence: After Becket's assassination, the castle was returned to the control of Becket as archbishop of Canterbury and remained a church property until the reign of Henry VIII when Hythe and Saltwood were seized by the Crown.
Split into simpler sentences: After Becket's assassination, the castle was returned to the control of the archbishop of Canterbury. Saltwood remained a church property until the reign of Henry VIII when Hythe and Saltwood were seized by the Crown.