Until the Wahhabi conquest of the Arabian peninsula at the turn of the last century, the mixture of sects there was as diverse as it was anywhere in the old pluralist Middle East. In its towns there lived, among others, Sufi mystics from the Sunni branch of Islam, members of the Zaidi sect, which is linked with the Shia branch of Islam, Twelver Shia traders, and seasonal Jewish farmhands from Yemen.

From the eighteenth century onward, successive waves of warriors from the Wahhabi revivalist movement, formed from Sunni tribesmen in the hinterland, have struggled to enforce a puritanical uniformity on the cosmopolitan coast. Toby Matthiesen recounts in The Other Saudis that, a few years after taking the eastern shores of the peninsula from the reeling Ottomans in 1913, Wahhabi clerics issued a fatwa obliging local Shias to convert to “true Islam.” In Hijaz, the western region that includes Mecca, Medina, and Jeddah, militant Wahhabi clerics and their followers ransacked the treasuries of the holy places in Mecca, lopped the dome off the House of the Prophet in Medina, and razed myriad shrines.

But their success was only partial. In 1930, when the Wahhabi Brethren began raiding Iraq and Jordan and upsetting the region’s British overlords, Abdulaziz al-Saud, the modern state’s founder, reined them in, slaughtering the zealots by the hundred.

Afterward, the peninsula regained much of its old tempo. Shia clerics applied their versions of Islamic law in the east. Jeddah’s newspapers continued to publish listings of Western as well as Islamic New Year’s Eve celebrations, cinema screenings, and concerts. Then, in 1979, apparently inspired by the Iranian overthrow of the Shah and the establishment of an Islamic republic earlier that year, Islamic militants stormed Mecca’s Grand Mosque, the holiest place in Islam, and declared a new order under a leader who proclaimed himself the Mahdi—the redeemer—and sought to replace the Saudi monarchy. Wahhabi forces loyal to the monarchy counterattacked, saved the al-Sauds, and retook the mosque. But a crucial deal was made: loyalist clerics approved the removal of the militants by force; but in return demanded that Saudi royals cede them power to strictly control personal behavior. The last cinemas and concert halls shut down. Women were obliged to shroud themselves in black.

Thirty-five years later, foreign descriptions of Saudi Arabia remain for the most part remarkably bleak. The writers of all four books under review examine the domination of the al-Saud…