The Secretary of State for the Colonies or Colonial Secretary was the British Cabinet minister in charge of managing the United Kingdom's various colonial dependencies.
The position was first created in 1768 to deal with the increasingly troublesome North American colonies, following passage of the Townsend Acts. Previously colonial responsibilities were held jointly by the Lords of Trade and Plantations and the Secretary of State for the Southern Department, who was responsible for Southern England, Wales, Ireland, the American colonies, and relations with the Catholic and Muslim states of Europe. Joint responsibility continued under the Secretary of State for the Colonies, but led to a diminution of the board's status and it became an adjunct to the new Secretary's Department.
Following the loss of the American colonies, both the board and the short-lived secretaryship were dismissed by the king on 2 May 1782; both were abolished later by the Civil List and Secret Service Money Act 1782 (22 Geo. 3, c 82). Following this, colonial duties given to the Home Secretary, then Lord Sydney. Following the Treaty of Paris 1783, a new board, named the Committee of Council on Trade and Plantations (later known as 'the First Committee') was established under William Pitt the Younger, by an Order in Council in 1784. In 1794 a new office was created for Henry Dundas — the Secretary of State for War, which now took responsibility for the Colonies, and was renamed the Secretary of State for War and the Colonies in 1801. In 1854, military reforms led to the Colonial and Military responsibilities of this secretary of state being split into two separate offices, with Sir George Grey becoming the first Secretary of State for the Colonies under the new arrangement.
In the latter part of the nineteenth century the United Kingdom also gained control over a number of territories with the status of "protectorate". The ministerial responsibility for these territories was initially held by the Foreign Secretary. However, by the early years of the twentieth century the responsibility for each of these territories had been transferred to the Colonial Secretary as well. The League of Nations mandated territories acquired as a result of the Treaty of Versailles (1919) became a further responsibility of the Colonial Office in the aftermath of the First World War.
In 1925 part of the Colonial Office was separated out as the Dominions Office, with its own Secretary of State. The new office was responsible for dealing with the Dominions together with a small number of other territories (most notably Southern Rhodesia).
In the twenty years following the end of the Second World War, much of the British Empire was dismantled as its various territories gained independence. In consequence, the Colonial Office was merged in 1966 with the Commonwealth Relations Office (which until 1947 had been the Dominions Office) to form the Commonwealth Office, while ministerial responsibility was transferred to the Secretary of State for Commonwealth Affairs (previously known as the Secretary of State for Commonwealth Relations). In 1968 the Commonwealth Office was subsumed into the Foreign Office, which was renamed the Foreign and Commonwealth Office (FCO).
The Colonial Secretary never had responsibility for the provinces and princely states of India, which had its own Secretary of State.
From 1768 until 1966 the Secretary of State was supported by an Under-Secretary of State for the Colonies (at times an Under-Secretary of State for War and the Colonies), and latterly by a Minister of State.