Beaumys Castle was a manor in the parish of Swallowfied, given to Sir Nicholas de la Beche in 1335.

De la Beche received a licence to crenellate in 1338 and produced a fortified manor house.

[2] De la Beche died, leaving the manor to his wife Margery, who in turn remarried,[1] to Thomas Arderne.

[3] On Arderne's death in 1347, however, John de Dalton and a small group of followers broke into the castle, where they killed Michael de Poynings, an important nobleman; terrified Lionel, the son of Edward III who was staying there at the time; stole £1,000 worth of goods, and seized Margaret, whom, as a wealthy widow, was forced to marry John.

The surrounding manor was broken up in 1420; the surviving earthworks are a scheduled monument.