The 26 year old Lieutenant [later Commander] Holbrook was awarded the VC, the first for the Royal Navy, for making the first submarine raid into the Dardanelles, on the 13th December, 1914.
Part of his citation reads:
"Lieutenant Holbrook was in command of the submarine B.11, an old and obsolete craft built in 1905. Not withstanding the difficulties of treacherous currents in the Straits, he dived under five rows of mines and torpedoed and sank the Turkish battleship "Messudieh," which was guarding the mine-field. He then succeeded in bringing the B.11 back to the Mediterranean, in spite of being attacked by gunfire and torpedo boats. When they got back to safety the B.11 had been submerged for nine hours."
 
Educated at Portsmouth Grammar School, he was the son of Sir Arthur Richard Holbrook, a newspaper publisher. One of five brothers. Between them, during the First World War, they earned a VC, DSO, MC and CBE, and their father was knighted for his services in commanding the Royal Army Service Corps' training unit.
 
Holbrook retired from the Navy in 1920 and afterwards spent most of his time farming and serving as chairman of the family publishing firm.
He passed away on 3 July 1976 at his home, Stedham Mill, Stedham, West Sussex, at the age of 87. He is buried at St James Churchyard, Stedham.
 
Holbrook is probably the only VC recipient to have a town and a local government area named after him. On 24 August 1915 amid a wave of anti-German feeling related to the First World War the name of the Australian town of Germanton was changed to Holbrook to honour the recent VC recipient. They built a park and erected a statue. They even bought an old Australian submarine to put on display. This was quite a feat considering that Holbrook is a considerable distance from the sea.
 
Holbrook subsequently visited the town on 3 occasions. He and the town maintained close relations up until his death. His widow, Mrs Gundula Holbrook, donated his medals, including the French Legion of Honour, to the Council of the Shire of Holbrook in 1982. In 1995 she made a substantial donation of $100, 000 towards the establishment of a submariners' memorial in the town and in 1997 visited the town to unveil it. A bronze statue of Lt. Holbrook stands in Germanton Park, Holbrook.