Shah Mohammad Reza Pahlavi’s fate was ultimately sealed when he fled Iran on January 16, 1979, although that outcome had probably been inevitable once mass demonstrations against his rule began in early 1977. But the roots of his unceremonious flight from the angry grasp of his former subjects were firmly planted in 1963, during the 15 Khordad demonstrations. These took place on, well, the 15th of Khordad, but that’s June 5 (and 6; they were a two day affair) for us Westerners. And not only did they establish the Shah’s unpopularity, but they also empowered the man who would ultimately replace him, Ayatollah Ruhollah Khomeini.
By the 1960s, dissatisfaction with the Shah’s increasingly autocratic rule was beginning to reach critical levels. Iranians were still angry about the 1953 coup that ousted the government of Mohammad Mosaddegh, but they were much angrier about a more fundamental problem: the Iranian economy was in tatters. Inflation was high, the government was running regular deficits despite a boom in oil revenues, the government had invested little in developing domestic Iranian industry, the housing market was overinflated, and there was no longer any democratic release valve for people’s frustrations, since the Shah was rigging every election to one degree or another. In the parliamentary election of 1961, the Shah decided to allow a more reformist slate of legislators to be elected and then appointed as prime minister Ali Amini, the former Iranian ambassador to the US. But the following year the Shah orchestrated Amini’s ouster before his program of land reform and broader political participation could turn him into another Mosaddegh (i.e., a royal pain in the ass, or rather a pain in the royal ass).
It was at this point that the Shah embarked on his own grand reform project, the “White Revolution,” intended to assuage public discontent and shore up his rule. Its main tenets included land reform to bring down costs for poor and middle class Iranians, the nationalization of some natural resources and privatization of some industries, women’s suffrage, and investment in education. It was immediately opposed, primarily on the land reform issue, by large landowners and the religious establishment (which itself controlled considerable amounts of land in the form of religious endowments). Extending the franchise to women and investing in secular (or, in some eyes, Western) education reform were also controversial for the religious elites. At the same time, the Shah implemented these reforms wholly on his own authority, and the increasingly dictatorial nature of his rule was enough to scare the Iranian middle class along with the religious elites and landowners. So the attempt at reform really caused more political strife than it was able to resolve.
On June 3, 1963 (which was Ashura that year), the disenchantment with the White Revolution was given a voice, and a face, when Khomeini addressed a crowd of demonstrators in the city of Qom in spite of government prohibitions. Khomeini called the Shah “wretched” and compared him to the Umayyad Caliph Yazid I, one of the most reviled figures in Shiʿa history. He was arrested the next day, and riots began the day after. Violent demonstrators took to the streets of the largest cities in Iran–Tehran, Qom, Mashhad, Shiraz, and others–attacking police and government offices. The following day the protesters took to the streets again, this time confronted by government security forces with “shoot to kill” orders. Estimates of the number of dead vary, from “thousands” according to the opposition to a scant 90 if you go by official government figures. Both sides were probably exaggerating, but I’d guess the figure was closer to “thousands” than to “ninety.”
Demonstrators continued to flood cities throughout the country, and hardliners close to the Shah recommended executing Khomeini. Cooler heads eventually convinced everybody that to martyr Khomeini would only inflame the situation further. Instead, Khomeini was kept under house arrest until April 1964. He was arrested again in November 1964, this time for speaking out against Iran’s subservient relationship to the US, and sent into exile, not to return to Iran until, well, you know.
The White Revolution proceeded apace, as did the Shah’s dangerous consolidation of power, but instead of expanding economic opportunities the reform simply allowed land wealth and oil revenue to concentrate among a slightly different upper class than had existed previously. The Shah’s education reforms worked fairly well–well enough that they created a whole new class of Iranians who were learned enough to realize just how badly they were getting screwed. Those people, angry at government corruption and frustrated at the lack of political freedom, turned to the Shiʿa clergy to champion their cause, and to Khomeini (despite his exile) in particular.