Somerton Castle is located approximately 1 mile (1.6 km) west of the village of Boothby Graffoe in Lincolnshire, England and to the south of the city of Lincoln, England. The site is on low-lying land between the Lincoln Edge and the River Witham. Although Somerton Castle is in the parish of Boothby Graffoe, it is in the Manor of Waddington and this portion is often referred to as the Manor of Somerton Castle. Antony Bek probably built the castle in 1281 and he gave it to King Edward II in 1309. King John II of France was imprisoned at Somerton Castle between 1359 and 1360, having been taken prisoner after the Battle of Poitiers. It continued as crown property until it was sold by Charles I in 1628, since when the castle has continued in private ownership.