Brownsea Castle Brownsea Castle Brownsea Castle, also known historically as Branksea Castle, was originally a Device Fort constructed by Henry VIII between 1545 and 1547 to protect Poole Harbour in Dorset, England, from the threat of French attack. Located on Brownsea Island, it comprised a stone blockhouse with a hexagonal gun platform. It was garrisoned by the local town with six soldiers and armed with eight artillery pieces. The castle remained in use after the original invasion scare had passed and was occupied by Parliament during the English Civil War of the 1640s. By the end of the century, however, it had
Brownsea Island instigator of Pride's Purge– the only military coup d'état in English history – was stationed on the island in 1654. Sir Robert Clayton, a Lord Mayor of the City of London and wealthy merchant became owner in the mid-1650s and after his death in 1707 the island was sold to William Benson, a Whig Member of Parliament and architect. He converted the castle into a residence and was responsible for introducing many varieties of trees to the island. In 1765 Sir Humphrey Sturt, a local landowner and MP purchased the island, which in turn passed to his sons. Sturt expanded