William Musgrave MP, (1518–1597) of Hayton Castle was an English politician, Member of Parliament for the Cumberland Division.
The 16th century saw tenancy by the Musgraves, who defended it against their sworn enemies, the Grahams and Armstrongs.
Sir Thomas also received the appointment of Marshal of Berwick, a town with a strategic castle on the eastern coast of England, bordering with Scotland.
The castle's location in the hotly disputed border region between England and Scotland made it one of the most important strongholds in the British Isles, and it enjoyed an eventful history.
As a major tactical objective in the region, the castle was captured by both the English and Scots on a number of occasions and frequently sustained substantial damage.