Though the United Arab Emirates did not gain full autonomy until 1971, their history has been traced back as far as 3000 B.C. It is known that there were mostly nomads living in the area at the time, herding and fishing for sustenance. Nothing really changed in the area for centuries, with the exception of the introduction of Islam, which at times either united or tore apart the region. By the mid-1900's, the main source of income in the area was from camel herding and the production of vegetables. Fishing and pearl diving also were important for the economy, but in a lesser role. Great Britain had been in control of the area for a long time, and after World War I the tide had started to turn and steps were being taken to hand over power. Oil was first drilled in UAE in 1958, but because of the ruler, Sheikh Shakbut, the importance of oil was not exploited. It was not until the family agreed that the brother, Zayed bin Sultan Al Nahayan, should take over as ruler in 1966, that the oil industry truly grew. With the support of Britain, the oil industry flourished in UAE. Finally, in 1971 Britain had handed over complete control to Zayed bin Sultan Al Nahayan, and today UAE has been able to flourish and become extremely well, especially for a country of it's size. In Abu Dhabi's last census, there were about 1 million citizens in the city. It is now the largest of the seven emirates that make up the nation.