The Dukedom of Berwick-upon-Tweed was created in 1687 for James FitzJames, the illegitimate son of King James II of England. The title, and its subsidiary titles (Baron Bosworth and Earl of Tinmouth) are generalloy considered to have been forfeit when the Duke was attainted following the deposition of his father. However, some have argued that the forfeiture was never properly carried out, and that the title thus remains extant, in the hands of the Spanish Duque de Penaranda.
The Duke of Berwick, James FitzJames, Marshal of France, was born at Moulins in the Bourbonnais, France, on August 21 1670.
During his fathers reign in England, he was created Duke of Berwick, Earl of Tinmouth, Baron of Bosworth, Knight of the Garter, Lord Lieutenant of Hampshire, Ranger of the New Forest, Governor of Portsmouth, successively Colonel of the Infantry and Cavalry Regiments, and Captain of the 3rd Troop of Life-Guards.
He was Duke of Berwick and Duke of Liria, and married Dona Catarina of Portugal, sister of the Duke of Veraquas.