The Admiralty was a department of the Kingdom of Great Britain and from 1801 of the Government of the United Kingdom that was responsible for the command of the Royal Navy.
Historically, its titular head was the Lord High Admiral – one of the Great Officers of State. For much of its history, from the early 18th century until its abolition, the role of the Lord High Admiral was almost invariably put "in commission" and exercised by the Lords Commissioner of the Admiralty, who sat on the governing Board of Admiralty, rather than by a single person. The Admiralty was replaced by the Admiralty Board in 1964, as part of the reforms that created the Ministry of Defence and its Navy Department (later Navy Command).
Before the Acts of Union 1707, the Office of the Admiralty and Marine Affairs administered the Royal Navy of the Kingdom of England, which merged with the Royal Scots Navy and then absorbed the responsibilities of the Lord High Admiral of the Kingdom of Scotland with the unification of the Kingdom of Great Britain. The Admiralty was among the most important departments of the British Government, because of the Royal Navy's role in the expansion and maintenance of the English overseas possessions in the 17th century, the British Empire in the 18th century, and subsequently.
The Admiralty Board, to which the functions of the Admiralty were transferred in 1964, is a committee of the tri-service Defence Council of the United Kingdom. This Admiralty Board meets only twice a year, and the day-to-day running of the Royal Navy is controlled by a Navy Board (not to be confused with the historic Navy Board). It is common for the various authorities now in charge of the Royal Navy to be referred to as simply 'The Admiralty'.
Since 1964, the title of Lord High Admiral of the United Kingdom has been vested in the monarch; the title was awarded to Prince Philip, Duke of Edinburgh by Queen Elizabeth II on his 90th birthday in 2011 and remained with him until his death in 2021. There also continues to be a Vice-Admiral of the United Kingdom and a Rear-Admiral of the United Kingdom, both of which are honorary offices.
The office of Admiral of England (later Lord Admiral, and later Lord High Admiral) was created around 1400; there had previously been Admirals of the northern and western seas. King Henry VIII established the Council of the Marine—later to become the Navy Board—in 1546, to oversee administrative affairs of the naval service. Operational control of the Royal Navy remained the responsibility of the Lord High Admiral, who was one of the nine Great Officers of State. This management approach would continue in force in the Royal Navy until 1832.
King Charles I put the office of Lord High Admiral into commission in 1628, and control of the Royal Navy passed to a committee in the form of the Board of Admiralty. The office of Lord High Admiral passed a number of times in and out of commission until 1709, after which the office was almost permanently in commission (the last Lord High Admiral being the future King William IV in the early 19th century).
In this organisation a dual system operated the Lord High Admiral (from 1546) then Commissioners of the Admiralty (from 1628) exercised the function of general control (military administration) of the Navy and they were usually responsible for the conduct of any war, while the actual supply lines, support and services were managed by four principal officers, namely, the Treasurer, Comptroller, Surveyor and Clerk of the Acts, responsible individually for finance, supervision of accounts, shipbuilding and maintenance of ships, and record of business. These principal officers came to be known as the Navy Board responsible for 'civil administration' of the navy, from 1546 to 1832.
This structure of administering the navy lasted for 285 years, however, the supply system was often inefficient and corrupt its deficiencies were due as much to its limitations of the times they operated in. The various functions within the Admiralty were not coordinated effectively and lacked inter-dependency with each other, with the result that in 1832, Sir James Graham abolished the Navy Board and merged its functions within those of the Board of Admiralty. At the time this had distinct advantages; however, it failed to retain the principle of distinctions between the Admiralty and supply, and a lot of bureaucracy followed with the merger.
In 1860 saw big growth in the development of technical crafts, the expansion of more admiralty branches that really began with age of steam that would have an enormous influence on the navy and naval thought. Between 1860 and 1908, there was no real study of strategy and of staff work conducted within the naval service; it was practically ignored. All the Navy's talent flowed to the great technical universities. This school of thought for the next 50 years was exclusively technically based. The first serious attempt to introduce a sole management body to administer the naval service manifested itself in the creation of the Admiralty Navy War Council in 1909.
Following this, a new advisory body called the Admiralty War Staff was then instituted in 1912, headed by the Chief of the War Staff who was responsible for administering three new sub-divisions responsible for operations, intelligence and mobilisation. The new War Staff had hardly found its feet and it continually struggled with the opposition to its existence by senior officers they were categorically opposed to a staff. The deficiencies of the system within this government department could be seen in the conduct of the Dardanelles campaign. There were no mechanisms in place to answer the big strategic questions. A Trade Division was created in 1914. Sir John Jellicoe came to the Admiralty in 1916. He reorganised the war staff as following: Chief of War Staff, Operations, Intelligence, Signal Section, Mobilisation, Trade.
It was not until 1917 that the admiralty department was again properly reorganised and began to function as a professional military staff. In May 1917, the term "Admiralty War Staff" was renamed and that department and its functional role were superseded by a new "Admiralty Naval Staff"; in addition, the newly created office of Chief of the Naval Staff was merged in the office of the First Sea Lord. Also appointed was a new post, that of Deputy Chief of the Naval Staff, and an Assistant Chief of the Naval Staff; all were given seats on the Board of Admiralty. This for the first time gave the naval staff direct representation on the board; the presence of three senior naval senior members on the board ensured the necessary authority to carry through any operation of war. The Deputy Chief of Naval Staff would direct all operations and movements of the fleet, while the Assistant Chief of Naval Staff would be responsible for mercantile movements and anti-submarine operations.
The office of Controller would be re-established to deal with all questions relating to supply; on 6 September 1917, a Deputy First Sea Lord, was added to the Board who would administer operations abroad and deal with questions of foreign policy. In October 1917, the development of the staff was carried one step further by the creation of two sub-committees of the Board—the Operations Committee and the Maintenance Committee. The First Lord of the Admiralty was chairman of both committees, and the Operations Committee consisted of the First Sea Lord and Chief of Naval Staff, the Deputy First Sea Lord, Assistant Chief of Naval Staff, and Fifth Sea Lord.
Full operational control of the Royal Navy was finally handed over to the Chief of Naval Staff (CNS) by an order in Council, effective October 1917, under which he became responsible for the issuing of orders affecting all war operations directly to the fleet. It also empowered the CNS to issue orders in their own name, as opposed to them previously being issued by the Permanent Secretary of the Admiralty in the name of the Board. In 1964, the Admiralty—along with the War Office and the Air Ministry—were abolished as separate departments of state, and placed under one single new Ministry of Defence. Within the expanded Ministry of Defence are the new Admiralty Board which has a separate Navy Board responsible for the day-to-day running of the Royal Navy, the Army Board and the Air Force Board, each headed by the Secretary of State for Defence.