Brownsea Island Brownsea Island Brownsea Island (also archaically known as "Branksea") is the largest of the islands in Poole Harbour in the county of Dorset, England. The island is owned by the National Trust. Much of the island is open to the public and includes areas of woodland and heath with a wide variety of wildlife, together with cliff top views across Poole Harbour and the Isle of Purbeck. The island was the location of an experimental camp in 1907 that led to the formation of the Scout movement the following year. Access is by public ferry or private boat; in 2017
Brownsea Island Viking raid to the harbour and used Brownsea as a base to sack Wareham and Cerne Abbey. In the 11th century the owner of the island was Bruno, who was Lord of the Manor of Studland. Following his invasion of England, William the Conqueror gave Studland, which included Brownsea, to his half-brother, Robert de Mortain. In 1154, King Henry II granted the Abbot of Cerne the right of wreck for the island and the abbey continued to control the interests of Brownsea for the following 350 years. After the Dissolution of the Monasteries, control of Brownsea passed to the Crown.