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.
On his appointment as Prime Minister in May 1940, Winston Churchill created for himself the new post of Minister of Defence. The post was created in response to previous criticism that there had been no clear single minister in charge of the prosecution of World War II. In 1946, the post became the only cabinet-level post representing the military, with the three service ministers – the Secretary of State for War, the First Lord of the Admiralty, and the Secretary of State for Air, now formally subordinated to the Minister of Defence.
On 3 September 1939, Neville Chamberlain, Prime Minister of the United Kingdom, reconstructed his existing government so as to be suited for the Second World War. The most dramatic change to the ministerial line-up saw the return of Winston Churchill as First Lord of the Admiralty. Other changes included Lord Caldecote replacing Lord Maugham as Lord Chancellor, Sir John Anderson replacing Sir Samuel Hoare as Home Secretary (Hoare became Lord Privy Seal with a wide-ranging brief) and the return of Anthony Eden to the government as Secretary of State for Dominion Affairs. However, the administration was not a true national unity government as it was made up primarily of Conservatives with support from some National Labour and National Liberal members. There were no representatives from the Labour Party or Liberal Party.