When Calouste Gulbenkian died in 1955 at the age of 86, he was the richest man in the world, known as 'Mr Five Per Cent' for his personal share of Middle East oil. The son of a wealthy Armenian merchant in Istanbul, for half a century he brokered top-level oil deals, concealing his mysterious web of business interests and contacts within a labyrinth of Asian and European cartels, and convincing governments and oil barons alike of his impartiality...