Carisbrooke is the island's only remaining medieval castle. Built on a Roman site the castle earthworks were begun in 1070.
The shell keep was built on the site some 70 years later. None of the Norman domestic buildings now remain. The imposing gatehouse with its drum towers dates from the 14th and 15th centuries.
In 1377 the French landed on the island but the castle was not attacked.
During Elizabethan times the threat of a Spanish invasion was avoided when the Armada was turned away at a nearby battle. However, the castle was considerably altered to resist the new artillery.
Outer lines of defence were built enclosing the old castle. The curtain walls, bastions and bulwarks remain in good condition to this day.
Charles I was held prisoner at the castle in 1647. An attempt to escape was foiled when he got stuck in the bars.
Later the castle was the occasional residence of the governor of the Isle of Wight and it became home to Princess Beatrice, youngest daughter of Queen Victoria, when she was governor.