There was oil. Astonishing, unbelievable, world-changing amounts of oil. Berg had discovered the southern point of what was later called the Ghawar field. It is so vast that it took geologists many years to realise that a well they struck more than a hundred miles north was actually drilling into the very same reservoir. The field stretches 175 miles north to south and 19 miles across; when you see it on a map it looks a little like a ballet dancer’s stretched leg.

