Gwyn Jenkins in the context of First Sea Lord and Chief of the Naval Staff

General (or full general to distinguish it from the lower general officer ranks) is the highest rank achievable by serving officers of the British Army and the Royal Marines. The rank can also be held by Royal Marines officers in tri-service posts, for example, Generals Sir Gordon Messenger and Sir Gwyn Jenkins, former Vice-Chiefs of the Defence Staff. It ranks above lieutenant-general and, in the Army, is subordinate to the rank of field marshal, which is now only awarded as an honorary rank. The rank of general has a NATO-code of OF-9, and is a four-star rank. It is equivalent to a full admiral in the Royal Navy or an air chief marshal in the Royal Air Force.

Officers holding the ranks of general, lieutenant-general and major-general are 'general officers' and may be addressed as 'general'.

His Majesty's Naval Service, referred to colloquially as the Royal Navy, after the primary fighting arm of the service, is the United Kingdom's naval warfare and maritime service. It consists of the Royal Navy, Royal Marines, Royal Fleet Auxiliary, Royal Naval Reserve, Royal Marines Reserve and Naval Careers Service. The Naval Service as a whole falls under the command of the Navy Board, which is headed by the First Sea Lord. This position is currently held by General Sir Gwyn Jenkins (appointed May 2025). The Defence Council delegates administration of the Naval Service to the Admiralty Board, chaired by the Secretary of State for Defence.

The Naval Service is dominated by the Royal Navy, and operates primarily from three bases in the United Kingdom where commissioned ships are based; Portsmouth, Clyde and Devonport, the last being the largest operational naval base in Western Europe. As of December 2025, there were about 90 vessels in service with the various branches of the Naval Service, plus more than 90 additional vessels operated by the supporting Serco Marine Services. These vessels included: 63 commissioned ships of the Royal Navy, 17 principal landing craft of the Royal Marines, 10 auxiliary ships of the Royal Fleet Auxiliary and 90+ supporting Marine Services vessels. Additional vessels are under charter to the Ministry of Defence. As of 2022, HM Naval Service (Royal Navy, Royal Marines, Royal Fleet Auxiliary and Naval Careers Service) employed about 39,500 regular and reserve personnel.

General (or full general to distinguish it from the lower general officer ranks) is the highest rank achievable by serving officers of the British Army and the Royal Marines. The rank can also be held by Royal Marines officers in tri-service posts, for example, Generals Sir Gordon Messenger and Sir Gwyn Jenkins, former Vice-Chiefs of the Defence Staff. It ranks above lieutenant-general and, in the Army, is subordinate to the rank of field marshal, which is now awarded as an honorary rank only. The rank of general has a NATO-code of OF-9, and is a four-star rank. It is equivalent to a full admiral in the Royal Navy or an air chief marshal in the Royal Air Force.

Officers holding the ranks of general, lieutenant-general and major-general are 'general officers' and may be addressed as 'general'.

First Sea Lord, officially First Sea Lord and Chief of the Naval Staff (1SL/CNS), is a statutory position in the British Armed Forces, held by an admiral or a general of His Majesty's Naval Service. As the highest-ranking officer in the Naval Service, the chief is the principal military advisor on matters pertaining to the navy and a deputy to the Secretary of State for Defence. The CNS is also a member of the Chiefs of Staff Committee and, thereby, a military advisor to the National Security Council, the prime minister and the monarch. The First Sea Lord is typically the highest-ranking officer on active duty of the Royal Navy unless the Chief of the Defence Staff is a naval officer. The post is currently held by General Sir Gwyn Jenkins.

Originally titled the "Senior Naval Lord to the Board of Admiralty" when the post was created in 1689, the office was re-styled First Naval Lord in 1771. The concept of a professional "First Naval Lord" was introduced in 1805, and the title of the office was changed to First Sea Lord on the appointment of Sir John "Jackie" Fisher in 1904. Since 1923, the First Sea Lord has been a member of the Chiefs of Staff Committee; they now sit on the Defence Council and the Admiralty Board.