On 28 January 1484, after several years of petitioning the
Edward IV, Sir Philippe de Carteret, seigneur of St. Ouen - recommended to the King's Grace by his father-in-law the first Governor of Jersey, Sir Richard Harliston, was granted a ″License to Crenelate″ - that is allowed to fortify his manor house. Although not mentioned in the permission, by local tradition, it has been suggested that De Carteret would have had access to the already-worked stone Grosnez Castle which could be re-used in fortifying St. Ouen's Manor. The financial savings could have been important to De Carteret, as - when he had come into his majority - ″trees grew in the Hall of the Manor because his guardians had wasted the substance of the Rentes″ i.e. - embezzled the income - and he was investing heavily in renovating the dilapidated manor buildings. A favourable marriage and connections may have been a factor to a noblemen whose family had enjoyed better financial circumstances when he married the daughter of the
Yorkist supporting Governor Harliston. But that marriage and connections led him into conflict with the second Governor of the island after 1486, Mathew Baker, who was appointed by the new
Tudor king,
Henry VII after Harliston had been removed from office by armed force following a siege at Gorey Castle. It has to be remembered that Henry VII had defeated
Richard III at the
Battle of Bosworth Field in 1485 which was the last significant battle in the
War of the Roses, an English civil war which had raged on and off for thirty years. Upon Matthew Baker's arrival, when Henry VII ordered a general examination of outstanding accounts by the Exchequer clerks, it was discovered that De Carteret had not paid his taxes to the Exchequer for three years. Since the death of Edward IV, De Carteret was already under some suspicion as a
Yorkist supporter, his father-in-law Harliston, the rebel had held out despite the Yorkists losing power, therefore it was inevitable that De Carteret would be required to pay the back taxes he owed the Crown and so began the long running dispute with Matthew Baker. Whether Sir Philippe actually used the stone from the ruined Grosnez Castle is not recorded. What is clear, however, is that by the 19th century, the archaeological excavations found that the castle's stones had been extensively robbed over the centuries, so perhaps he did. In 1806, a naval signal station to send messages to
Guernsey was established at Grosnez near to where the present racecourse grandstand and other buildings are. It was unconnected to the castle or ruins. Title to the Castle passed to the Seigneurs of Rozel from the Seigneurs of St. Ouen. (date and citation needed). == Earlier history ==