On February 8, 2015, at least 40 people were killed in a stampede and clashes between police and football supporters at a Cairo stadium.

It is the latest episode of violence involving some of Egypt's most hardcore football fans, known as ultras. This film, made in 2014, chronicles their story.

During the 2011 Egyptian uprising that saw Hosni Mubarak removed from power, millions of Egypt's most die-hard football fans played an important role.

These fans, ultras, first emerged in Egypt in 2007. They come from different social backgrounds, hold a mix of  political views and do not subscribe to an individual party - but they are united in their steadfast allegiance to their teams. The most popular clubs are Al-Ahly whose fans are known as "Ultras Ahlawy" and Zamalek whose supporters are called the "White Knights".

The ultras had one voice. They energised people. It's thrilling to see 5,000 young men marching in the streets, speaking with one voice.

Hassan El-Mistikawy, sports analyst 

Ultras are known for challenging authority. At the start of the Egyptian revolution in 2011, they joined other Egyptians calling for change.

"Since 2007, we've been the victims of severe injustice at the hand of the authorities. They did the worst things to us. They arrested many of our comrades. We've been humiliated. Naturally, we were the first to take to the streets," says Mustafa Abdel Zaher, a White Knights ultra.

At matches, ultras have often clashed with security forces. During the revolution, they took their intensity, organisation and anti-authoritarianism to the streets.

"They knew how to fight with the police," Saeed Sadek, a professor of sociology, explains.

The ultras involvement in the revolution and its aftermath has been touched by tragedy. They have been killed and wounded, both at the start of the revolution and in the protests that followed - like those that took place on Mohammed Mahmoud Street in Cairo in November 2011.

Then in February 2012, a riot broke out at a match in Port Said, where the home Al-Masry fans attacked Cairo's Al-Ahly supporters with explosives, knives and broken glass.

In what became known as the Port Said massacre, at least 72 Al-Ahly supporters were killed and more than 500 people were injured. Most of those killed were teenagers. Some witnesses said the security forces were complicit by failing to stop the violence.

After the massacre, the interim Egyptian government banned domestic league football for two years. Spectators remain banned from any match between Egypt's six major football clubs, including Al-Ahly, Zamelek and Al-Masry.

In this documentary, filmmaker Alma Mosbah explores the culture of the ultras, their role in the Egyptian revolution, and how different violent events have affected them. The film also explores the anguish of ultras' family and friends, who still await justice for their young men who have been killed.