The Movement of 15 Khordad marks a critical moment in Iran's political history, occurring in response to the arrest of the influential religious leader Ayatollah Ruhollah Khomeini. Khomeini had been a vocal critic of the Shah's policies, advocating for a more Islamic governance in Iran. His arrest ignited widespread anger among the populace, who began to organize protests across numerous cities, including Tehran, Tabriz, and Mashhad. Demonstrators expressed their frustration with the oppressive measures of the Pahlavi regime, including political repression, Westernization efforts, and the Shah's increasingly autocratic rule.

As protests grew, the government responded with force, deploying military tanks and paratroopers to quell the unrest. The confrontation between citizens and armed forces led to significant casualties, with reports of hundreds killed and injured. The events of 15 Khordad galvanized public sentiments against the Shah, marking a shift in the Iranian socio-political landscape. This was not only a reaction to an individual's arrest but also a broader discontent with authoritarian rule and foreign influence in Iran. The violent repression of the movement intensified opposition and paved the way for subsequent sizeable mobilizations, culminating in the Iranian Revolution of 1979.

Khomeini would emerge as a leading figure of the revolution, demonstrating the powerful role of religious leadership in Iranian politics. This episode illustrated the interplay between political and religious spheres in Iran, foreshadowing the deep-seated changes that would follow. The Movement of 15 Khordad remains a significant chapter in the narrative of Iran's struggle for justice and sovereignty against perceived tyranny.