In 1351 Henry of Grosmont, a great-grandson of Henry III, was created the 1st Duke of Lancaster for services in the Hundred Years War. The seat of Lancaster in Lancashire was raised to a county palatine.[notes 1] This meant the area would now be ruled by hereditary noblemen possessing special authority and autonomy from the rest of the Kingdom of England. Although the noblemen swore allegiance to the king, they had the power to rule the county and its contiguous land largely independently of the king. All other properties attached to the Duchy of Lancaster, including the Savoy, then became subject to the laws of the Duke. As a consequence, someone being pursued for a debt in London could reside in the Savoy without fear of arrest by people acting under the authority of The Crown. Royal writs would not be enforceable within the County of Lancashire until the 19th century. Lancaster had its own Court of Chancery until the 1970s. These circumstances have been used in historical fiction, such as the Aubrey-Maturin novels by Patrick O'Brian.