Sited in the middle of the Isle of Wight the castle began life around 1000 AD when the Anglo Saxons built a wall around the hill to defend themselves against Viking raids, soon after the Norman invasion of 1066 a castle was built within the existing defences.

In 1100 Carisbrooke was granted to Richard de Redvers, and over the next two hundred years his descendants carried out an extensive building programme at the castle. The last Redvers resident Countess Isabella de Fortibus sold it to King Edward I shortly before she died (1293) and the castle has remained a crown property for many years.
Later development of the castle was largely influenced by the threat of invasion from France and Spain.

The castle was also used to imprison King Charles I who arrived at Carisbrooke in November 1647. He twice tried to escape, but his attempts failed and he remained at the castle until September 1648, just five months before his execution in Whitehall.
The castle has been the official residence of the governor of the Isle of Wight until the death of the last resident governor, Princess Beatrice, in 1944. Since then it has been managed as an ancient monument.