
The Aden Protectorate was a British protectorate in southern Arabia which evolved in the hinterland of the port of Aden and in the Hadramaut following the conquest of Aden by Great Britain in 1839, and it continued until the 1960s. In 1940 it was divided for administrative purposes into the Western Protectorate and the Eastern Protectorate. Today the territory forms part of the Republic of Yemen.

The Alawi Sheikhdom, or Alawi — was a Sheikhdom located in the Aden region of southwestern Yemen. Its capital was Al Qasha. The state was abolished in 1967 with the independence of the People's Republic of South Yemen.

‘Aqrabi, or the Aqrabi Sheikhdom, was a state in the British Aden Protectorate, the Federation of Arab Emirates of the South, and its successor, the Federation of South Arabia. Its capital was Bir Ahmad. The state was abolished in 1967 with the independence of the People's Republic of South Yemen. The area is now part of the Republic of Yemen.

Beihan or Bayhan, officially the Emirate of Beihan, was a state in the British Aden Protectorate and the Federation of South Arabia. Its capital was Suq Abdulla, now called Beihan. The Emirate was abolished in 1967 upon the founding of the People's Republic of South Yemen and is now part of the Republic of Yemen.

The Chief Commissioner's Province of Aden was the administrative status under which the former Aden Settlement (1839–1932) was placed from 1932 to 1937. Under that new status, the Viceroy of India assumed direct control over Aden, which had hitherto been administered by the government of the Bombay Presidency. The Aden Protectorate remained unaffected by this change.

Lahej, the Sultanate of Lahej, or, sometimes, the Abdali Sultanate, was a Sheikdom based in Lahej in Southern Arabia. The Sultanate became self-ruled in 1728 and gained independence in 1740. In 1839, the Sultanate became Aden Protectorate of the British Empire, though nominally the 'Abdali Sultan retained his status. The Aden Protectorate was briefly ruled again by the Ottomans during World War I, but regained by the British and absorbed into Federation of South Arabia in 1963. The 'Abdali dynasty was officially abolished in 1967, with the proclamation of South Yemen.

The Federation of South Arabia was an organization of states under British protection in what would become South Yemen. It was formed on 4 April 1962 from the 15 protected states of the Federation of Arab Emirates of the South. On 18 January 1963 it was merged with the Crown colony of Aden. In June 1964, the Upper Aulaqi Sultanate was added for a total of 17 states. A team was sent to the 1966 Commonwealth Games in Kingston, Jamaica. The Federation was abolished on 30 November 1967, when its status as a British protectorate came to an end, along with that of the Protectorate of South Arabia, and they became the People's Republic of Southern Yemen.

The State of Aden was a state constituted in Aden within the Federation of South Arabia. Following its establishment on 18 January 1963 Sir Charles Hepburn Johnston stepped down as the last Governor of Aden.