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.
Royal Navy
The Royal Navy (RN) is the United Kingdom's naval warfare force. Although warships were used by the English kings from the early medieval period, the first major maritime engagements were fought in the Hundred Years War against the Kingdom of France. The modern Royal Navy traces its origins to the early 16th century; the oldest of the UK's armed services, it is known as the Senior Service.