This story goes all the way back to 1744, when the ambitious but unremarkable clan of al-Saud, one of many clans that divided up the vast Arabian desert, allied with a puritanical fundamentalist named Muhammed ibn al-Wahhab.
The al-Saud clan allied with Wahhab and his followers, known as Wahhabis, who in their fervor could fight as well as preach. The deal was simple: the Wahhabis would help the al-Sauds expand through conquest from a tiny sliver in the Arabian peninsula's central desert to a vast empire, and in return the al-Sauds would adopt Wahhabism as official policy. It worked.
The Saudi empire collapsed in 1818, defeated by the much stronger Ottoman Empire, which seized much of the Arabian peninsula for itself. But Wahhabist Islam had taken root, and the Wahhabis and the al-Sauds maintained their strategic alliance from 1744 through today.
Because Saudi rulers need the Wahhabis' support to stay in power. They need their loyalty, they need the civil society that the Wahhabi clerical establishment creates, and they also need the ideological justification for the vast, young, and in many ways artificial Saudi empire.
When Abdulaziz al-Saud - (the founder of SAUDIA ARABIA) - was born, in 1876, the area we today know as Saudi Arabia was a patchwork of tribal leaders, many of them loyal to the Ottoman Empire or, later, the British Empire. Abdulaziz wanted to restore his family's former empire. He knew that, like his forefathers, he would need the help of the Wahhabis and the zeal they brought to the battlefield. So he formed a band of quasi-renegade fundamentalist militias known as the Ikhwan, or brothers. As before, the deal was simple: the Ikhwan would fight on behalf of al-Saud, and in exchange could impose their ultra-conservative Islam on whomever they conquered.
By the late 1920s, al-Saud and the Ikhwan had conquered most of today's Saudi Arabia. Al-Saud, a pious Muslim but also a forward-thinkin