Millennium Promenade - Southsea Castle

In the spring of 1544, fearful of a French attack on Portsmouth, King Henry VIII ordered work on a new castle to command the deep water channel into Portsmouth where ships came closest to the shore.

Southsea Castle was completed in the record time of six months, partly funded by monies raised from the disposal of monastic sites.

Henry was afraid of a combined invasion by France and Spain, in the wake of his conflict with the Pope over his divorce, and so the castle was one of a series of forts built along the south coast.

Southsea Castle is important. It is the first record we have of the name ‘Southsea’ being used and the castle itself represented the very latest thinking in military architecture.

Rounded medieval towers represented too vulnerable a target for cannon fire and provided too little flanking cover. Southsea Castle was therefore built with a square keep, rectangular gun platforms and angled bastions, which reduced the size of the target. Guns sited in the flanks of the bastions provided all-round cover.

It may have been from the ramparts of Southsea Castle that King Henry VIII watched his fleet sail out to meet a French invasion force on 18 July 1545 and saw, to his horror, his great ship the Mary Rose capsize with terrible loss of life. Fortunately the French did not land in Portsmouth (they did on the Isle of Wight), but the scare was sufficient to justify some further expenditure on the defences of the town.

The Mary Rose was raised from the seabed in 1982. A state-of-the-art £27 million Mary Rose Museum opened in Portsmouth Historic Dockyard in 2013. The ship is the only 16th-century vessel on display anywhere in the world.

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