Box 1: Two diaries covering Osborne's service on HMS CONQUEROR, HMS VINDICTIVE and other warships during the First World War, covering the period 20 January 1915 to 19 June 1918. With loose material including naval signals, memoranda, newspaper cuttings, entertainment programmes and photographs. Also invitation cards for the presentation of the Freedom of the Borough of Dover to Vice-Admiral Sir Roger Keyes, 12 December 1918. Leather wallet displaying carte de visite photographs of Queen Victoria and other members of the Royal family. Mounted photograph by W.O. Kirk of West Cowes showing soldiers and dignitaries waiting for Prince Henry at Carisbrooke Castle, 1889.
Box 2: Scrapbook circa 1851-1915 relating to the family history of Osborne's wife Joan Marion Herbert Master. She was the daughter of Godfrey Cornewall Chester Master, and sister of Mary Augusta Grace Master, first wife of Vice-Admiral the Hon. Arthur Stopford (1879-1955).

Administrative / biographical background
Osborne was the second son of Captain Herbert Boyles Osborne, 53rd Regiment. He entered the Navy as a cadet in 1897. As a midshipman he was involved in the relief of Peking and Tientsin during the Boxer Rebellion in 1900. After promotion to lieutenant he specialised in gunnery and during the early part of the First World War he served as gunnery officer on the battleship HMS CONQUEROR. He was executive officer with the rank of commander on board the same vessel during the Battle of Jutland in 1916. His next appointment was flag commander under Vice-Admiral Keyes in the Dover Patrol. He was awarded the DSO in recognition of his role in fitting out the cruiser HMS VINDICTIVE at Chatham and the subsequent raids on the ports of Ostend and Zeebrugge in 1918. After promotion to captain in 1920, he was given command of destroyer flotillas in the Atlantic and Mediterranean fleets. In 1930 he became Commodore in command of the Atlantic Fleet destroyers. During periods of service at shore establishments, he had duties at the League of Nations and commanded the Gunnery Schools at Devonport and Portsmouth. Osborne was promoted to vice-admiral and placed on the retired list in 1937. He was Vice President and then President of the Ordnance Committee of the Royal Arsenal at Woolwich in 1936-1940. His knowledge of gunnery also resulted in his appointment as President of the Air Gunnery Technical Board at the Ministry of Aircraft Production in 1940-1941.