Calshot Castle


Part of the Cotton Manuscripts collection, this drawing of a circular keep with curtain wall, embrasures for cannons as well as traditional arrow slits, may be a ‘platt’ (or plan) for a proposed tower at Calshot. 

Calshot castle was located at the entrance to Southampton Water from the Solent and was built in 1539-40, at a time of large scale coastal survey and fortification. During this period, the southern coast of England was under threat of invasion from the combined forces of France and Spain. France was England’s historical enemy and King Henry VIII’s divorce from Catherine of Aragon had offended the militantly catholic Charles V, Holy Roman Emperor and 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.

Full title:
Drawing of an unidentified fort
c. 1525-1550
Manuscript / Illustration
Usage terms

Public Domain in most countries other than the UK.

Held by
British Library
Cotton Augustus I i f.80

Full catalogue details

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