Records of the Colonial Office, Commonwealth and Foreign and Commonwealth Offices,...

In 1794 a Secretary of State for War was appointed to manage the war with France. After the peace of 1801 his responsibilities appeared to have declined and the administration of the colonies was transferred to him and he became Secretary of State for War and the Colonies. When war was resumed in 1803 military activities again became his main pre-occupation, but he retained the colonies.

The restoration of peace in 1815 and the increased demands which the acquisition of new colonies during the war had imposed meant that his colonial responsibilities then became paramount, and by 1822 the office included four Geographical Departments dealing with colonies in different areas of the world. Between 1804 and 1836 the War and Colonial Department was responsible for relations with the Barbary States, but in 1836 this responsibility was transferred to the Foreign Office. On the outbreak of the Crimean War in 1854 colonial and military affairs were divided and a separate Secretary of State for the Colonies was appointed.

In 1854 a separate Colonial Office, headed by a Secretary of State for the Colonies, was established. The division of the office into geographical departments was continued, general business being entrusted to the chief clerk. In 1870 a General Department took some of the work of the chief clerk, an Accounts Branch was set up in 1869, and there was a separate Emigration Department from 1878 to 1894.

In 1907 a Dominions Division was set up; in 1925 this became the separate Dominions Office, though until 1930 and again briefly in 1931 and 1938 to 1939 the offices of Secretary of State for the Colonies and Secretary of State for Dominions Affairs were held by the same person. The remaining geographical departments were grouped in a Crown Colonies Division. The territories mandated to Britain following the First World War were also administered by the Colonial Office. From 1907 to 1925 it was responsible for the work of the Imperial Institute.

From 1930 the number of subject departments increased considerably, a trend which accentuated during the Second World War. The granting of independence to growing numbers of colonies in the post-war period and the termination of mandates led to a decrease in the responsibilities of the Colonial Office. Relations with the former colonies became the concern of the Commonwealth Relations Office. In July 1961 responsibilities for overseas aid and development formerly borne by certain departments and committees of the Colonial Office were transferred to the new Department of Technical Co-operation, and a number of technical advisers were transferred with them.

In March 1962 responsibility for relations with Northern Rhodesia and Nyasaland was transferred to the Central African Office, which was under the personal control of the Home Secretary. From July 1962 to October 1964 the titles of Secretary of State for the Colonies and Secretary of State for Commonwealth Relations were combined, and in 1966 the Colonial Office was merged with the Commonwealth Relations Office to form the Commonwealth Office.