The command flag of a Rear Admiral, RN belonging to Admiral Sir Hugh Paget Sinclair (1873-1939). It is made of silk, is machine-sewn and has a cord at the hoist. The flag is likely to have been a presentation item. It has a white field with a red cross overall and two red discs in the hoist quarters.

Admiral Sir Hugh Paget Sinclair (1873-1939) specialised in torpedo work before World War One, during which he commanded HMS 'Renown' and was Chief of Staff of the battle-cruiser force. He became Director of Naval Intelligence from 1919 to 1921. Sinclair was promoted to Rear-Admiral in 1920, becoming Chief of the Secret Service in 1923. Priorities between the wars were at first intelligence gathering from Soviet Russia and then, in the 1930s, the belligerent intentions of Germany, Italy and Japan. Sinclair was in favour of offering concessions to Germany at the time of the Munich agreement. He died shortly after the outbreak of World War II.