Calshot Castle  

This is a drawing of a circular keep with curtain wall, embrasures for cannons as well as traditional arrow slits. It may be a ‘platt’ of a proposed tower at Calshot which was considered by the Earl of Southampton and Lord St John from boats on 18 March 1539. Calshot castle was located at the entrance to Southampton Water from the Solent and was built during the 1539-40 a time of large scale coastal survey and fortification. This was due to Henry VIII’s fear of an invasion from the combined forces of France and Spain. In 1538 Francis I of France, and Charles V Holy Roman Emperor and King of Spain signed a peace treaty. This union gave rise to the possibility that France and Spain may combine forces to invade England. France was England’s historical enemy and Henry VIII’s divorce of Catherine of Aragon, Charles V’s aunt, had offended the militantly catholic King of Spain. The close proximity of Calshot to the important naval base of Portsmouth meant that this area figured prominently in the defensive strategy. In order to deny enemy access to Southampton Water it was proposed that a stone tower be built at the eastern end of a long shingle spit that extends across the mouth of the Water from its western shore.

drawing and extract taken from the British Museum online archive

drawing: ink and tempera on parchment

date: 1539