Admiralty
It evolved from *Admiralty Navy War Council, (1909–1912) which in turn became the Admiralty War Staff, (1912–1917) before finally becoming the Admiralty Naval Staff in 1917. It was the former senior command, operational planning, policy and strategy department within the British Admiralty. It was established in 1917 and existed until 1964 when the department of the Admiralty was abolished, and the staff departments function continued within the Navy Department of the Ministry of Defence until 1971 when its functions became part of the new Naval Staff, Navy Department of the Ministry of Defence.
Mobilisation Division (Royal Navy)
The Mobilisation Division was established on 8 January 1912 it evolved out of the Naval Mobilisation Department of the Admiralty and was part of both the Admiralty War Staff and Admiralty Naval Staff departments. Mobilisation ceased to be a Naval Staff division on 12 January 1918 when it was re-designated an admiralty department that would now report to the Office of the Second Sea Lord until 1932.