Edited sentence: 642–679), record extremely detailed statistics for ethnic and religious affiliation of the inhabitants at the city and village level taken at the time that the area was still an Ottoman district (until 1912-1914) and free of religious suppression of the Shias that followed with the Saudi takeover.8, Oman and Central Arabia, pp.From such sources, the historic and strong Shia character of the region and its oases is easily ascertained.Lorimer (Gazetteer of the Persian Gulf, 1915, vol.The British colonial sources, such as J.With the discovery of the world's largest oil fields (the Ghawar Field which is almost totally inside the traditional al-Hasa district), the area has achieved an extraordinary economic and strategic importance to the Saudi state, leading to more than usual tampering with the ethnic and religious statistics for the area produced by that state