played a role in the Glorious Revolution of 1688 against Charles' brother, King James II. The townsfolk of Deal seized their local castle in support of William of Orange, and took steps to defend the Downs against a feared Irish invasion which never materialised. Southsea Castle was held by the King's illegitimate son, James FitzJames, the Duke of Berwick, who was pressurised into surrendering as his father's cause collapsed. Yarmouth was controlled by Robert Holmes, a supporter of James, but was prevented from actively supporting the loyalist cause by the local inhabitants and his garrison, who sided with William. 18th–19th centuries 1700–91 The military significance of the Device Forts declined during the 18th century. Some of the fortifications were redesigned to provide more comfortable housing for their occupants. Cowes Castle was partially rebuilt in 1716 to modernise its accommodation, demolishing much of the keep and adding residential wings and gardens over the landward defences, and Brownsea Castle began to be converted into a country house from the 1720s onwards. Walmer became the official residence of the Lord Warden of the Cinque Ports, and Lionel Sackville, the Duke of Dorset, carried out extensive work there after 1708. There was probably some rivalry between Sackville and the naval officer Sir John Norris, who redeveloped nearby Deal Castle during the same period, creating comfortable wood-panelled quarters for himself there overlooking the sea. Criticisms were levelled at the defences of the Device Forts, which often had minimal garrisons and had been left to fall into disrepair. Southsea Castle, for example, was only garrisoned by "an old sergeant and three or four men who sell cakes and ale" according to one contemporary account, and proposals were put forward to abandon the site altogether. Portland suffered badly from coastal erosion and, protected only by a caretaker garrison, was reportedly not repaired for many years, and a 1714 survey found the long-neglected Pendennis Castle to be "in a very ruinous condition". The French military dismissed Deal, Walmer and Sandown as being highly vulnerable to any potential attack, describing them in 1767 as "very old and little more than gun platforms". Mersea Fort and East Tilbury fell into ruin and were abandoned, the latter being submerged by the Thames. Some limited investments were made in the fortifications, however, with the defences of Pendennis Castle being modernised in the 1730s, and those of Calshot in the 1770s. 1792–1849 The