The cause of yesterday's celebration was that 27 May 2008 marked the 100th anniversary of the creation of the Ahmadi Khalifat, a succession of leaders who would guide the community following the death of the religion's founder Mirza Ghulam Ahmed in 1908.

Many religions believe in some sort of messianic figure who will return to earth to restore justice - Judaism has the Messiah, Christianity has Christ, Hinduism has Krishna and Islam has the Mahdi, as prophesied by Muhammad.

Ahmadis believe that in the late nineteenth century Mirza Ghulam Ahmed, a controversial and colourful Indian religious figure, was not only the Mahdi but that he was the successor to the prophet Muhammad. He also declared that Jesus (known as Isa in Islam) survived his crucifixion, recovered and went in search of the lost tribes of Israel - eventually settling in Kashmir where he died at the ripe old age of 120.

This set him at odds with both Christians and Muslims but nonetheless by the time of his death in 1908 more than 300,000 people had joined the new faith. Since then the religion has grown enormously. The community claims to have 200 million believers (20,000 in England alone) and also claims to be the fastest growing sect within Islam. Other estimates place the population at a much lower number, somewhere in the region of 40million.

But the journey has been anything but easy. Most mainstream Muslims believe that the return of Jesus will come after the Mahdi and that the Ahmadis are heretical for believing that Ghulam Ahmed was the messiah.

In 1984 the Pakistani government, spurred on by hardline mullahs, banned the Ahmadis from proselytising and officially labelled them non-Muslims. Shortly afterwards the fourth Kalif moved his headquarters to Britain.

Watching the thousands of families gather for prayers yesterday it struck me how strange it was that the birth of a South Asian Muslim sect was being celebrated in East London. Many people I spoke to expressed sadness that the celebrations could not be held in Pakistan and joy at the fact that, despite the odds, their religion had survived.

But it also reminded me just how strong the connections between Ahmadism and Britain are. Ahmadis formed a prominent number of early emigres to Britain in the early twentieth century and in 1924 they built the Fazal Mosque in Putney - the first mosque in London.

In 2003 they built the largest mosque in Europe, the Bait al Futuh in Morden (pictured above). Although it's worth pointing out that when they did the Muslim Council of Britian - the country's most prominent Muslim umbrella organisation - issued a statement saying it was not a mosque because Ahmadis are not Muslims.

In the meantime, every year thousands of Ahmadi pilgrims travel to the UK to seek an audience with the current Kalif, Mirza Masroor Ahmed.

Prominent Ahmadis I spoke to yesterday were also emphasising how the Ahmadi Community has traditionally rejected violence despite repeatedly being victims of persecution themselves. They emphasised how the faith's founder, Ghulam Ahmed, repeatedly told his followers to engage in "the jihad (struggle) of the pen and word".

Rafiq Hayat, the National President of the Ahmadiyya Community in Britain, told me: "Public perception of Islam is often tainted by the way it is portrayed in the media - with zealots preaching hate-filled diatribe and calling for violence. That is not Islam."

Ahmadism's motto, plastered on the walls of the Excel centre yesterday, reads: "Love for all, hatred for none" and I couldn't help but think in the current climate those words were not only a fitting testament to the story of Ahmadism, but also our story now.