<P> In the early 18th century, the Al Qasimi dynasty established itself in Ras Al Khaimah and Sharjah on the Arabian Peninsula, growing to become a significant maritime force with holdings on both the Persian and Arabian coasts . In 1819, a British naval force was sent from Bombay in order to suppress alleged piracy - actions of the Al Qasimi fleet against British flagged shipping that affected trade routes in the Strait of Hormuz, along the Persian Gulf coast, and the Indian Ocean . </P> <P> In the Battle of Ras Al Khaimah of 1809, the Al Qasimi fleet was largely destroyed . The British operation continued to Linga on the Persian coast which was, like the Greater and Lesser Tunbs islands, administered by the Al Qasimi . The attack on Ras Al Khaimah resulted in the destruction of the tower of the 16th century Dhayah Fort whose remains can be seen at Rams in northern Ras Al Khaimah . In January 1820, the British imposed the General Maritime Treaty of 1820 signed by Sheikh Sultan Bin Saqr Al Qasimi who was reinstated by the British in Ras Al Khaimah after the deposition of Hasan Bin Rahma . The treaty stipulated the end of piracy and slavery, and laid the foundation for the British protectorate over the Trucial States that lasted until 1971 . In 1869, Ras Al Khaimah became fully independent from neighbouring Sharjah . However, from September 1900 to 7 July 1921, it was re-incorporated into Sharjah; the last governor became its next independent ruler . </P> <P> On 10 February 1972, Ras al - Khaimah, under the leadership of Sheikh Saqr bin Mohammad al - Qasimi, joined the United Arab Emirates . </P> <P> Its rulers were: </P>

When did ras al khaima join the emirates