The Islamic Republic's 31st anniversary was unlikely to pass without incident. However, reformist and opposition figures have been left disappointed with their achievements.
Mass celebrations at Azadi Square, in central Tehran, were greeted by Mahmoud Ahmadinejad. The president appeared to make good his promise to deliver a "telling blow" to the west: he declared that Iran was now a nuclear state, with the capacity to enrich uranium to 20 per cent.
One day they said we cannot enrich uranium, but with the resistance of our leader, nation . . . and with the help of God, the Iranian nation has become nuclear.
The reformist "Green Movement" had planned demonstrations to express popular discontent with the lack of democratic accountability and representation in Iran. However their attempts were quashed by a security apparatus clearly prepared for them. The movement had declared that "each Iranian is a media outlet", but their attempts to use technology to co-ordinate their protests were disrupted by blocks on Gmail and weak internet connections.
Demonstrators were met by the Basiji and Revolutionary Guard, who ensured that large groups of oppositionists could not congregate. The tactics appear to have been effective, leaving a representative of the National Iranian American Council to conclude on its live blog:
One thing I'm struck by is just how much the government has been in control today. Sure, they chartered busses and lured tens of thousands to the official government rally with free food, but they have also managed to keep the opposition activities largely on their terms today.
Despite the government's tight management of the main scene in Tehran, there have been reports of clashes with notable political figures.
Ayatollah Khomeini's granddaughter has reportedly been arrested, along with her husband, a brother of Mohammed Khatami.
Mehdi Karroubi's car was attacked and a number of his followers were arrested, including his youngest son, Ali. Karroubi himself suffered pepper spray and tear gas burns. You can read an interview with one of his sons here.
Reports from later in the day have claimed that Mir Hossein Moussavi's wife, Zahra Rahnavard, was attacked by plain-clothed militia forces. It is said that postings on Moussavi's website corroborate these claims.
Attacks on high-profile reformist individuals are likely to add weight to calls for accountability and justice, fuelling the demonstrations against the government. Events may have been state-managed well today but the reformists' message remains the same. Although the government isn't teetering towards revolution as some commentators may claim, tensions continue to fester and seem unlikely to disappear.