Oil exploration in Persia
In 1889, with a substantial fortune, D'Arcy and his family moved to England, where he bought the Stanmore Hall mansion, a house on Grosvenor Square and rented Bylaugh Park. His wife, Elena, died in 1897 and, in 1899, he married Nina Boucicault (a first cousin of her namesake, celebrated Irish stage and film actress Nina Boucicault), with whom he lavishly entertained guests. He had acquired a strong interest in horse-racing while in Australia, and maintained a private box at Epsom racecourse.
In 1900, he agreed to fund a search for oil and minerals in Persia headed by Wolff, Ketabchee and Cotte, although D'Arcy never visited Persia himself. Negotiations with the Mozaffar al-Din Shah Qajar began in 1901, and with the offer of £20,000 (£2.1 million today), for a sixty-year concession to explore for oil – later, the D'Arcy Concession – was secured in May, covering 480,000 square miles (1,200,000 km2), and stipulated that D'Arcy would have the oil rights to the entire country except for five provinces in Northern Iran. In exchange, the Iranian government was given 16% of the oil company's annual profits, an agreement that would remain in effect until the nationalisation of the industry by the Iranian government in March 1952.
A drilling team under George B. Reynolds was sent to Chiah Surkh and drilling commenced at the end of 1902. Despite drilling a producer in January 1904, D'Arcy had already spent £160,000, and was overdrawn at Lloyds Bank by £177,000. D'Arcy was forced to find further financial support, and in 1905 the Concession Syndicate was established with Burmah Oil Company Ltd. as a major investor, and D'Arcy's operation a subsidiary. More importantly, operations moved to the Shardin region in 1906.
Drilling in southern Persia at Shardin continued until 1907, when the search was switched to Masjed Soleyman (Masjed-e-Sulayman in Persian مسجد سلیمان), in a place named Maydon-e-Naftune. Drilling began at one site in January 1908, and at another nearby in March. By April, with no success, the venture close to collapse, and D'Arcy almost bankrupt, he decided, with Burmah, to abandon exploration in Iran. In early May 1908, they sent Reynolds a telegram stating that they had run out of money and ordering him to "cease work, dismiss the staff, dismantle anything worth the cost of transporting to the coast for re-shipment, and come home". Reynolds delayed following these orders and in a stroke of luck, struck oil at 1,180 feet (360 m) shortly after on 26 May 1908.
In April 1909, D'Arcy was appointed a director of the newly founded Anglo-Persian Oil Company (APOC), which would later become British Petroleum (BP). By 1911, APOC had run a pipeline from the find to a refinery at Abadan. In 1912, the Mount Morgan company was listed in London, and D'Arcy was made chairman of that board.
The financial support given by Burmah Oil and the British Admiralty meant that D'Arcy could no longer put his name to the new company despite the best efforts of his wife, and so was a shareholder.
