Hallifax joined
HMS Britannia in 1899 and served as a Naval Advisor in Turkey, for which he was awarded the . During the First World War served as first lieutenant and torpedo lieutenant on board . After being attached to the Inter-Allied Commission in Berlin he served in
HMS Valiant, Home Fleet, from 1921 to 1923. He then attended various disarmament meetings at
Geneva and was promoted captain in 1924. Two years later he commanded the cruiser , of the
China Squadron, remaining there until 1928. He was later appointed naval attaché in Paris and also served in that capacity in Madrid, Brussels and The Hague. He returned to active naval duties when he was appointed to command of from 1932 to 1934. In 1935 he became Director of the Signal Division of the Admiralty, and was promoted Rear-Admiral, retired, in the same year. On the outbreak of
World War II in 1939, he was recruited by the South African government to organise a navy, which was named the
Seaward Defence Force. ==South African Navy==