From Strange Rebels: 1979 and the Birth of the 21st Century, by Christian Caryl (Basic Books, 2014), Kindle Loc. 4676-4704:
Many of the events of 1979 are linked with the mysterious power of anniversaries. The Communist Party in Poland feared the incendiary potential of the nine-hundredth anniversary of the martyrdom of a saint. The thirtieth anniversary of the Communist takeover in China was shrewdly exploited by Deng Xiaoping and his colleagues to reinforce the sense of a new beginning. The forty-day Islamic mourning cycle proved a crucial dynamic for the revolution in Iran—as did the millennial expectations of Khomeini’s followers, whose habit of referring to him as the “imam” fanned a longing for the realm of justice promised by the reappearance of the Hidden Imam. Indeed, the Islamic calendar itself was one of the many issues that fueled the discontent of Iranian believers. The shah’s decision to introduce a new, non-Islamic calendar in the mid-1970s served as yet another bit of evidence to good Shiites that the monarch was an enemy of their religion—and gave Khomeini’s supporters yet another potent argument.
In the Julian calendar of the West, 1979 is not an especially evocative date. But this was not true for Muslims. In the Islamic calendar, which is based on the phases of the moon and takes as its start the Prophet’s exile from Mecca in 622, the Western month of November 1979 coincides with the dawning of the new year of 1400. According to certain traditions, that is the year that the Mahdi, the Islamic messiah, is supposed to reveal himself to the faithful and usher in a new age of eternal justice. For Iranians, this is the moment when historical time and the forces of eternity coincide, and this apocalyptic expectation fueled the fervor with which Khomeini was greeted as the country’s new savior. Some demonstrators wondered whether he might, indeed, turn out to be the Imam of the Age himself; some of the faithful even claimed to have seen his face on the moon.
In the Kingdom of Saudi Arabia, a group of provincial zealots came up with a particularly fateful reading of the Mahdi myth. Like the majority of Saudis, they were not Shiite but Sunni, and they hailed from a remote corner of the kingdom that had largely missed out on the new prosperity. In November 1979, as pilgrims were arriving for the annual hajj, the obligatory pilgrimage to Mecca, heavily armed members of the group took over the al-Masjid al-Haram, the Grand Mosque, and took thousands of pilgrims from around the world hostage. They then announced that one of their leaders, a young man named Abdullah Hamid Mohammed al-Qahtani, was the Mahdi, the long-prophesied redeemer of Islam. All Muslims, they said, were religiously obligated to obey his commands. The Saudi authorities declined to do this and immediately set about the task of clearing the mosque. It took them weeks, covertly assisted by a team of commandos lent to the kingdom by the French government, to kill or capture the hostage takers. In the end, according to official Saudi figures, 270 people—hostages, hostage takers, and members of the assault force—lost their lives. Foreign diplomats who managed to get access to local hospitals concluded that the actual death toll was much higher, closer to 1,000.
The leader of the group, Juhayman al-Otaibi, was captured and executed a few weeks after the end of the siege. But his ideas would prove prophetic. He had categorically denounced the corruption of the Saudi regime and rejected the presence of infidel foreigners in a country that was supposed to be the undefiled home to Mecca and Medina, two of the three most holy places in Islam. (The third is the Dome of the Rock in Jerusalem.) A subsequent generation of Saudi radicals—Osama bin Laden among them—would not forget.