Page "History of Qatar" Paragraph 2

During the 1950s and 1960s gradually increasing oil revenues brought prosperity, rapid immigration, substantial social progress, and the beginnings of Qatar's modern history.

When the U. K. announced a policy in 1968 ( reaffirmed in March 1971 ) of ending the treaty relationships with the Persian Gulf sheikdoms, Qatar joined the other eight states then under British protection ( the seven trucial sheikdoms — the present United Arab Emirates -- and Bahrain ) in a plan to form a union of Arab emirates.

By mid-1971, as the termination date of the British treaty relationship ( end of 1971 ) approached, the nine still had not agreed on terms of union.

Accordingly, Qatar declared independence as a separate entity and became the fully independent State of Qatar on September 3, 1971.