King Henry VIII had this fortification, as well as its sister castle at St. Mawes, built in about 1542 to protect Falmouth harbour. It was also part of the Cornish end of a chain of coastal artillery fortresses to counter military threats from France and Spain.
Stephen von Haschenperg, a German engineer from Moravia, was employed to
design and oversee the construction.
Decorative details on the building, such as windows, doors and moulding profiles were
probably designed by the King’s master mason, John Molton.
In Queen Elizabeth I’s reign, a new and much larger rampart was added around the original fortress.
Early in 1646, just prior to the Civil War, it was host to Queen Henrietta Maria and her son, the Prince of Wales, the future Charles II before they sailed to the Isles of Scilly and then France. During that conflict the fortress, under the command of the 70 year-old Sir John Arundel and aided by Sir Henry Killigrew, withstood a five month long siege before becoming the penultimate Royalist stronghold to surrender on 17th August 1646.
It is currently in the care of English Heritage and is open to the public.