Extending across most of the northern and central Arabian Peninsula, Saudi Arabia is a young country that is heir to a rich history. In its western highlands, along the Red Sea, lies the Hejaz, which is the cradle of Islam and the site of that religion’s holiest cities, Mecca and Medina. In the country’s geographic heartland is a region known as Najd (“Highland”), a vast arid zone that until recent times was populated by nomadic tribes. To the east, along the Persian Gulf, are the country’s abundant oil fields that, since the 1960s, have made Saudi Arabia synonymous with petroleum wealth. Those three elements—religion, tribalism, and untold wealth—have fueled the country’s subsequent history.