In 1922, the British government secured undertakings from the rulers of the Trucial States not to sign concessions with foreign companies without their consent. Aware of the potential for the development of natural resources such as oil, following finds in Persia (from 1908) and Mesopotamia (from 1927), a British-led oil company, the Iraq Petroleum Company (IPC), showed an interest in the region. The Anglo-Persian Oil Company (APOC, later to become British Petroleum, or BP) had a 23.75% share in IPC. From 1935, onshore concessions to explore for oil were granted by local rulers, with APOC signing the first one on behalf of Petroleum Concessions Ltd (PCL), an associate company of IPC. APOC was prevented from developing the region alone because of the restrictions of the Red Line Agreement, which required it to operate through IPC. A number of options between PCL and the trucial rulers were signed, providing useful revenue for communities experiencing poverty following the collapse of the pearl trade. However, the wealth of oil which the rulers could see from the revenues accruing to surrounding countries such as Iran, Bahrain, Kuwait, Qatar and Saudi Arabia remained elusive. The first bore holes in Abu Dhabi were drilled by IPC's operating company, Petroleum Development (Trucial Coast) Ltd (PDTC) at Ras Sadr in 1950, with a bore hole taking a year to drill and turning out dry, at the tremendous cost at the time of £1 million.