On 28 October, tens of thousands of Iranians from various parts of the country gathered at the tomb of King Cyrus the Great (Kourosh in Persian) in Pasargadae some 800 km south of Tehran to celebrate the day commonly recognised as his birthday. While the occasion is not inscribed in the country's official calendar, it has soared in popularity and grown exponentially in terms of participants over the last few years. Cyrus the Great was the founder of the Achaemenid Empire and reigned from 559 to 530 BCE. According to historians, he created the largest empire the world had then yet seen. Last month, a copy of an official letter banning travel to the Pasargadae was circulated on social networks in Iran. Despite this, members of nationalist networks encouraged each other to take part in the gathering to show that such measures would not stop them from expressing their sentiments. Videos of the gathering dominated Iran's cyberspace and showed participants chanting “Iran is our country, and Cyrus is our father.” Others chanted against the ruling system, with some expressing support for the Pahlavi Dynasty that ruled Iran before 1979. In that year, the then shah, Mohamed Reza Pahlavi, was dethroned by the Islamic Revolution. According to the Fars Province prosecutor in Iran, Ali Salehi, the organisers of the October gathering were arrested and charged with spreading “anti-values” through slogans chanted during the gathering. Grand Ayatollah Nouri Hamedani, a Shia marja-i taqlid (source of emulation) remarked that “these people are against the revolution. I wonder how they can gather around Cyrus's tomb and chant slogans [praising Cyrus] that we chant about our supreme leader. Who has failed in his duty by allowing these people to gather,” he asked. Under the secular rule of the shah before 1979, propaganda empowered nationalist fervour in Iran. The Islamic calendar was substituted with the Iranian royal calendar in 1976. The Iranian calendar, which had earlier begun with the migration (hijra) of the Prophet Mohamed from Mecca to Medina, now started with the coronation of Cyrus the Great. Ayatollah Ruhollah Khomeini, the later leader of the Islamic Revolution then in exile in Najaf in Iraq, labelled the use of the new calendar haram (forbidden by Islamic Law) and a “preamble to the elimination of Islam” in Iran. Like many other pious Muslims, Khomeini viewed nationalism as un-Islamic. He thought it was in opposition to the concept of the ummah (the Muslim community), which rejects the borders that divide Muslim societies. He said that “nationalism is designed by plotters to create discord among the Muslims and is being propagated by the agents of imperialism.” Khomeini further said that “the plan of the great powers and their affiliates in the Muslim countries is to divide the various strata of the Muslims, whom God, the Blessed and Exalted, has declared to be brothers… Those who in the name of nationalism or factionalism create schism and disunity among Muslims are the armies of Satan, the opponents of the Holy Quran, and are agents of the superpowers.” Conservatives in Iran today view nationalism, essentially a secular movement that advocates the separation of state and religion, as a serious threat to the foundation of the state, which is based on the “guardianship of the Islamic jurists.” During the 28 October gathering at Cyrus's tomb, one of the slogans chanted was “freedom of thought cannot take place with beards,” a reference to the figures now in power in Iran. Iranian nationalists glorify the country's pre-Islamic civilisation and reject the Islamic political system, though not necessarily Islam. They feel that the Iranians were humiliated as a result of the Arab-Muslim conquest of Iran, which led to the collapse of the Iranian Sassanid Empire in the 7th century CE. Among radical nationalists anti-Arab sentiments are particularly intense, and the country's conservatives that dominate the establishment view this as troubling because the Prophet Mohamed was an Arab, the Quran is in Arabic and the Shia Imams were of Arab descent. A new version of Iranian nationalism emerged under the presidency of Mahmoud Ahmadinejad from 2005 to 2013, when he began to advocate religious nationalism promoting an Iranian-Islamic identity. In 2010, Ahmadinejad began stressing nationalistic Iranian themes in an attempt to carve out a new political constituency among those who identified with religion, whether conservative or reformist. Ahmadinejad's chief of staff at the time, also said to be his religious mentor, Esfandiar Rahim-Mashaei, developed a discourse that provoked uproar in Iran. In a speech in 2010 Rahim-Mashaei said that “there are different interpretations of Islam, but our understanding of the real nature of Iran and of Islam is the Iranian school. From now on, we must present to the world the school of Iran.” He added that “without Iran, Islam would be lost. If we want to present the truth of Islam to the world, we should raise the Iranian flag.” Rahim-Mashaei was attacked by conservatives from every corner of the country, but Ahmadinejad defended him and blamed the critics for not understanding the depth of such views. Since Ahmadinejad left office in 2013, the idea of religious nationalism in Iran has not been promoted or advocated by any particular group, although this does not mean that the ideology is dead. The gathering under the banner of Cyrus during the October celebration has thus presented an opportunity for the domestic opposition to express its protest against the ruling system in the country, though it was noteworthy this year that neither the police nor the security forces appeared on the scene to disperse the crowds. Unlike during more typical situations where pro-government plainclothes groups physically confront demonstrators, these were not present during the 28 October demonstration. But as the movement gains momentum and the slogans directed against the establishment become more threatening, it is likely that at some point the riot police will become involved and prevent the gatherings from happening. Whether such measures will be faced peacefully by the demonstrators or lead to clashes similar to those in the aftermath of the 2009 disputed presidential elections in Iran remains to be seen. The writer is a political analyst writing about Iranian affairs, the Middle East and US foreign policy in the region.