History: Kuwait's modern history began in the early 18th century, when several clans from the Al Aniza tribe migrated to the northern shore of the Gulf from Saudia Arabia. Their economic prosperity was based on fishing, pearling, and trade. Eventually the Al Sabah emerged as the dominant clan, and were formally established as rulers in 1756. By the late 19th century, however, fears of growing Ottoman influence led Sheikh Mubarak Al Sabah (r.1896-1915) to enter into an agreement with Great Britain, which effectively established Kuwait as an autonomous British protectorate. Under the 1899 agreement, Kuwait maintained control over its internal affairs, while Great Britain assumed responsibility for the country's security and foreign relations. In the mid-1930s work began on the development of Kuwait's petroleum industry, the basis of the country's modern prosperity. Oil was first discovered in Kuwait in 1938. The commercial export of crude oil began in June 1946. By the 1960s Kuwait enjoyed a level of economic development that made it one of the richest states in the world on a per capita basis. In 1963 Kuwait became a member of the United Nations. In the early hours of August 2, 1990, Iraq invaded Kuwait. What followed was seven months of brutal occupation of Kuwait by the Iraqi forces. It was a period of agony and suffering. A UN-backed military operation began on January 17, 1991. 18 countries joined the operation which took 42 days to oust the Iraqi occupation force. Kuwait was finally liberated on February 26, 1991. However, most services and operations were restored in record time. The present day Kuwait shows no sign of the arson and vandalism the Iraqis left behind.