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 neighbours, 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.
On 2 December 1971, Sheikh Rashid ibn Humayd Al Nuaimi joined the United Arab Emirates.
Rulers
Its rulers were:
* 17.. – 17.. Sheikh Rashid ibn Hamid Al Nuaimi
* 17.. – 1816 Sheikh Humayd ibn Rashid Al Nuaimi
* 1816 – 1838 Sheikh Rashid II ibn Humayd Al Nuaimi (d. 1838)
* 1838 – 1841 Sheikh Humayd II ibn Rashid Al Nuaimi (1st time) (d. 1873)
* 1841 – 1848 Sheikh `Abd al–`Aziz I ibn Rashid Al Nuaimi (d. 1848)
* 1848 – 1873 Sheikh Humayd II ibn Rashid Al Nuaimi (2nd time)
* 1873 – April 1891 Sheikh Rashid III ibn Humaid Al Nuaimi (d. 1891)
* April 1891 – 8 July 1900 Sheikh Humaid III ibn Rashid Al Nuaimi (d. 1900)
* 8 July 1900 – February 1910 Sheikh `Abd al–`Aziz II ibn Humayd Al Nuaimi (b. 18.. – d. 1910)
* February 1910 – January 1928 Sheikh Humayd IV ibn `Abd al–`Aziz Al Nuaimi
* January 1928 – 6 September 1981 Sheikh Rashid IV ibn Humayd Al Nuaimi (b. 1904 – d. 1981)
* 6 September 1981 – 20.. Sheikh Humayd ibn Rashid Al Nuaimi (b
