This watercolour of the thirteenth-century Salisbury Tower, in the south-western corner of the Lower Ward of Windsor Castle, was commissioned by Queen Elizabeth shortly after the end of World War II. The topographical artist Claude Muncaster was asked to provide accurate records of the Castle buildings, a project which was initially conceived as a response to the threat of aerial attack during the war. Muncaster was subsequently commissioned to paint watercolour views of Balmoral and Sandringham.