Ajman enjoys being located in the middle of the Emirates as a whole. On 8 January 1820, Sheikh Rashid ibn Humayd Al Nuaimi signed the General Maritime Treaty with Britain, accepting a protectorate to keep the Ottoman Turks out. Like four of Ajmān's neighbors, Sharjah, Dubai, Ras al-Khaimah and Umm al-Qaiwain, its position on the route to India made it important enough to be recognized as a salute state (albeit of the lowest class: 3 guns).

History sits visibly in Ajman : traces of the old town are still visible, as in the shape of the fine old watchtower at the town's entrance, and the large fort in the town's centre. Yet Ajman - which now is the northernmost part of the Dubai-Sharjah-Ajman coastal urban belt - is in no way resting on its considerable history.

Prior to gaining independence in 1971, Ajman formed part of the Trucial States – so called due to a series of treaties signed by their ruling families with the British in the 19th century. These treaties, initiated from 1820 onwards, originally concerned issues of piracy in the Gulf, but were eventually extended until Britain had acquired exclusive rights of foreign representation over the territories – making them in effect colonial possessions. It was a relationship that suited both parties, providing the sheikhdoms with protection from Ottoman encroachment and foreign aggression, while securing the British with a valuable naval base to protect their maritime shipping.

On 2 December 1971, Sheikh Rashid ibn Humayd Al Nuaimi joined the United Arab Emirates.