Once Upon a Time in Iran is a road movie featuring pilgrims and presidents: a journey to the spiritual heartlands of the Iranian people and a tale of martyrdom that has helped define their view of aggressors and the outside world.

Directed by BAFTA award-winner Kevin Sim - this documentary follows pilgrims on a breathtaking spiritual journey through Iran and Iraq. It reveals how the murder of Husayn ibn Ali at the Battle of Karbala in 680 CE still shapes Iranian identity. The anniversary of his death is called Ashura and it is a day of mourning and religious observance for Shi'ah Muslims. The film follows a group of ordinary Iranians to the source of this tale - on pilgrimage to Kerbala. All the pilgrims travel to Iraq in the knowledge that increasingly in recent months these Shi'a shrines - and Shi'a pilgrims - have become targets of Iraqi Sunni attacks.

Amongst the pilgrims on this modern Canterbury Tales are Basijis, hard-line revolutionary guards, supporters of President Ahmadinejad and the tough fundamentalist principles of the Islamic Republic; bazaari, the enormously influential traders from the great bazaars of Tehran and Isfahan; athletes from the closely guarded Zoorkheneh, the so called Houses of Strength, the guardians of centuries-old traditions, whose extreme exercise regime is driven by the stories and ancient poetry of Iran. Also amongst the pilgrims will be three-year-old Mohammad Hussein, learning these stories for the first time.