At the end of the civil wars of 1139-53, King Stephen's chief lieutenant William of Ypres gave the churches of Throwley and Chilham to the Abbey of Saint Bertin in Saint-Omer, France. Throwley Priory was built as a cell of that Benedictine house. It was dissolved as part of Henry IV's general suppression of alien priories in 1414 and granted to Thomas Beaufort, the half-brother of the king's father. Beaufort gave Throwley to Syon Abbey on 13 July 1424, a gift confirmed by Henry VI in 1443.