The Admiralty and Marine Affairs Office (1546–1707), previously known as the Admiralty Office (1414–1546), ^[1] was a government department of the Kingdom of England, responsible for the Royal Navy. First established in 1414 when the offices of the separate Admiral of the North and West were abolished and their functions unified under a single centralised command, it was headed by the Lord High Admiral of England. The department existed until 1707 when England and Scotland united to form the Kingdom of Great Britain, after which it was known as the British Admiralty.

Under Henry VIII, the Admiralty supervised the creation of a "Navy Royal",^[2] with its own secretariat, dockyards and a permanent core of purpose-built warships.^[3] It later helped repulse the 1588 Spanish Armada during the 1585 to 1604 war with Spain, although attacks on the Spanish mainland were far less successful. By the end of the 16th century, corruption within the Admiralty had seriously weakened the Royal Navy, leading to a government enquiry and calls for naval reform.

Although a small permanent navy was first established during the ninth century,^[4] it quickly disappeared and pre-16th century monarchs largely relied upon requisitioned merchant ships for their needs. Maritime affairs were managed directly by the Crown until the appointment of a Lord High Admiral in 1385, ^[5] with administration and operations divided into three regions, the North Sea, English Channel and Irish Sea, each commanded by an admiral.^[6] These regional commands were abolished in 1414 and their functions and jurisdiction centralised under a single Admiralty Office,^[7] although they did not disappear entirely disappear; the Admiral of the Narrow Seas, first established in 1412, continued to exist as a separate command subordinate to the Lord High Admiral.^[8]

As the Royal Navy expanded under Henry VIII of England, increasing costs and complexity required the appointment of specialist departments, including Clerk of the Acts, Comptroller of the Navy (Navy Board), Treasurer of the Navy and Surveyor of the Navy. In 1546, these offices and functions were brought together in the Council of the Marine, a group directed by the Lieutenant of the Admiralty until 1557.^[9] Later known as the Navy Board, this was the first permanent attempt to establish an effective naval administration, with responsibility for ship building, maintenance and administration of the Royal Navy Dockyard, although operational matters remained under the Lord High Admiral.^[10]

A fifth officer, the Surveyor of Marine Victuals, was added in 1550 with responsibility for food and drink, along with a Board of Ordnance under a Master of the Ordnance, an independent body which supervised the storage and issuing of weapons and gunpowder at the main naval Bases. For the next six decades, this system of administration did not change, except in 1557 the Treasurer of the Navy took over supervision of the Navy Board, which remained independent until 1628 when it became a subsidiary body of the Board of Admiralty. The Treasurer also reported independently to the Lord High Treasurer in order to provide funds for the navy, although spending and administration remained the responsibility of the Navy Board.

During the 16th century, the Admiralty consisted of the Lord Admiral of England, supported by the Vice-Admiral of England and the Lieutenant of the Admiralty, responsible for the control and direction of naval operations, civil affairs, logistical support and judicial administration of the admiralty courts.

By 1560 there were three main operational areas; the English Channel, Irish Sea and North Sea, each with its own squadron commanded by an admiral or vice admiral.^[21] The number of ships varied depending on circumstances while some were purely temporary formations but during this period they included the following;

Narrow Seas Squadron; also called the "Eastern" and commanded by the Admiral of the Narrow Seas, responsible for protecting English shipping in the Channel, particularly the Straits of Dover, and the area of the southern North Sea between England and the Spanish Netherlands, later the Dutch Republic.^[22]

Irish Squadron; a temporary formation in service from 1539 to 1545 and 1569 to 1583, based in Milford Haven under the Admiral of the Irish Squadron.^[23][24][25]

North Sea Squadron; based first in Great Yarmouth, then Newcastle upon Tyne under the Admiral of the North, responsible for the northern North Sea; established in 1543, it was disbanded in 1563.^[24] Included^[26]

Channel Squadron; responsible for guarding the western approaches to the Channel and renamed the "Western Squadron" in 1650, this was formed in 1512 and based in Plymouth under the Vice-Admiral in the Channel.^[27]

Before the formation of the Council of the Marine in 1545, court officials of various monarchs of England responsible for administering the king's ships were called 'Clerks of the Kings Marine'. In 1545 a memorandum was issued by Henry VIII outlining a new organization to be called the 'Council of the Marine, formalized by Letters Patent in April 1546, and consisting of the Chief Officers of the Admiralty as they were then called. In 1578 The council of Marine is renamed the Navy Office and administered by the Navy Board. The chief officers become later known as principal officers and commissioners.^[30]

In the 19th and 20th centuries referred to as the Justice Department of the Royal Navy.