From the mosque to the bagel shop, this is the real Brick Lane

Bangladeshis branded the depiction of Brick Lane in Monica Ali's eponymously titled novel as 'despicable'. Now the area is back in the media spotlight as the setting for a controversial new TV drama. Nick Ryan ventures into the heart of east London to uncover the true face of 'Banglatown' and its people

Five hundred years ago, it was a green, grassy virgin. Its villages are now swallowed beneath grey streets; its clogged veins littered with history. It wears its age heavily, but opens its embrace to poor and rich alike. Popularised by Monica Ali's novel Brick Lane, it is a fusion of rural Bangladesh and East End vigour. But this is only its latest incarnation. It has had many names; many faces.

Sandwiched between Spitalfields and Whitechapel, "Banglatown" has been called the spiritual heart of the East End. Writers from Dickens to Wilde and Sir Arthur Conan Doyle have been drawn here, setting their stories amid the folds of its crime, dissent and poverty.

This is where Jack the Ripper and the Kray Twins once roamed. Where Stalin and Trotsky shared a flat, and the suffragettes had their headquarters. Municipal socialism was born in the lanes around Hawksmoor's East End churches, while the fictional villain Fu Man Chu was said to reside among Limehouse's infamous opium dens. It is where the forthcoming BBC1 drama England Expects is set, about a man (Steven Mackintosh) sucked back to his far-right roots. Frank Deasy, the writer, and I as the show's creative producer, met immigrants and white extremists living in the area as part of our research.

Brick Lane and the surrounding East End are where generations of the poorest immigrants fetch up: whether "lascar" sailors jumping ship from Sylhet or Ashkenazi Jews fleeing Russia's pogroms. The new arrivals have worked in sweatshops, clashed with the indigenous population, before making the area their own, then finally moving on out.

Irish immigrants fought native English beneath the same skies in the race riots of 1736. French Huguenot refugees melted into the London fabric, while Jewish gangs battled each other, before making way for the Sylhetis of Bangladesh. This history of struggle and change is imprinted on the buildings, such as the former Huguenot chapel, then Methodist church, synagogue and mosque on the corner of Brick Lane and Fournier Street.

Today, the beat of Banglatown's heart is contained in the tongues of a hundred nations; her rhythm the call to prayer, mixing with the rough hip-hop of her sound systems. Drugs are taking hold among a nominally Muslim youth. Unemployment and overcrowding are high. Her synagogues are mostly silent, but there are still some signs of Jewish identity - the stone masons at the entrance to Brick Lane itself - which speak of an age only recently past.

It is here that I have met my fellow author, Hari Kunzru, the novelist, whose seminal work, The Impressionist, tells its own story of changing identity. But there are other stories, too, if you look away from the curry houses and trendy bars which snake along Brick Lane's length; into areas where the name Monica Ali is not well-liked. From the yellowing bowels of Aldgate East tube, down the Roman-straight expanse of Whitechapel Road, you walk past the little park commemorating Altab Ali, the tailor murdered by white racists more than two decades ago. Clothed in the sweat and grease of a late summer's day, past sullen pubs which seem to lean inwards, within spitting distance of the ancient Whitechapel Bell Foundry, you approach the impressive, modern bulk of the East London Mosque.

On a Friday evening, as dusk draws down, the streets and alleyways around the mosque swarm with the faithful. Arab, Bangladeshi and African flow like a river into the great building. Behind it, the old Fieldgate Street Great Synagogue is almost lost, swallowed by the rising steel skeleton of the new London Muslim Centre - an all-Muslim business and research site - crafted to the side of the mosque. It is a mirror, almost, to the glittering shapes of the City skyscrapers and Docklands looming close by.

Surprisingly, mosque and synagogue share excellent relations. Muhammad Bari, the mosque's chairman - a lean, neatly-dressed man who was once an officer in the Bangladesh Air Force (and is deputy secretary of the Muslim Council of Britain) - told me from inside his sweltering, whitewashed office: "Although we feel differently about the injustices on Palestine, in Islam we are asked to live peacefully with our neighbours. We're all people of The Book." During Yom Kippur, for example, all work was ceased on the London Muslim Centre out of respect for the Jewish festival.

In our conversations, Dr Bari spoke at length of the identity crisis which has swamped the Bangladeshi population, driving a wedge between old and young. And it is here that a new identity is being forged in response. Followers of a progressive Islam that takes hold where the Salvation Army was born, in an East End which, at one time or another, has called itself home to religious radicals, from Levellers and Ranters, to Anabaptists, Fifth Monarchy Men and Quakers.

Siraj Salekin is my guide into this world: into the real Brick Lane; into the heart of Banglatown, part of the Islamic Umma - or worldwide community - that calls so powerfully among these troubled peoples. A passionate speaker with a soft, whiskered face and shining eyes, the 37-year-old graduate and father of five remembers the day he arrived in Britain. The day he moved to Brick Lane. He said: "I came here during the dustbin strike of Lord Callaghan. We took the taxi from the airport and I saw all the bins and I said I wanted to go back home; back to my green land. But I've been here since."

Siraj is a modest man, falling into a fast, tripping speech when gripped by fervour. This speech slows and his voice takes on a tremble as he talks about the father who came to Britain but refused to become British; who eventually left to settle back in rural Sylhet and has now passed away.

He said: "My dad was quite educated. He was a policeman in the British forces.He used to say we had blood in every brick in this country. We sweated out back home in British factories; then when we came here we did it again. This country became prosperous on our backs."

Siraj has made it his mission to understand his own background, travelling to Sylhet to build an impressive family tree. He made a point of understand his own faith, twice completing the haj pilgrimage to Mecca. He has bound both together to make a documentary about the roots of the community. He shows it to those for whom a gang is the closest thing to family. "There's a huge identity crisis with the youngsters here," Siraj said. "I want to educate people. Often I find they don't know who they are. When they know who they are, they can stand on their two feet and feel proud." He shakes his head, recalling how Bengali "uncles and aunties" have been attacked and mugged by their own youth.

Siraj has taken part in the struggles to change the face, and fate, of Banglatown: leading 2,000 people in a human chain to protect the site next to the mosque from commercial development. Building Mosque Towers, a mini-skyscraper, which is the country's first all-Asian pensioners' home. And helping to create the Tower Hamlets Council of Mosques, as well as other school and faith initiatives. Picking a chilli - "real Bengali chilli, very hot" - from one of the house plants he so loves but says his wife despises, Siraj suggests that I should consider "reverting" (converting) to Islam. "We are all born pure in the eyes of God," he told me, smiling.

Siraj introduces me to Joe Ahmed-Dobson, the lightly bearded youngest son of Frank Dobson MP, the former government minister. Joe, 27, is a revert. A West Ham fan, too, who takes his Bengali nephew to matches. Both Siraj and Joe are admirers of Tariq Ramadan. Ramadan is the grandson of the founder of the Muslim Brotherhood in Egypt. He argues it is time to develop a more moderate, less "literalist" European Islam. "The problem with Muslims is that they know too much history," half-joked Joe, a charity fundraiser who carries some semblance of his father's face in his broad nose and brow. "We're always looking backwards and blaming everything."

During the rest of my visits, Siraj introduces me to a wide array of others. Among them is Shafiur "Shafi" Rahman. Shafi's father was one of Britain's first Bangladeshi travel agents. Today, he manages Nafas, a community-sensitive drug project. Counselling and medication - and occasionally faith, if requested - are used to tackle Banglatown's burgeoning drugs problem. "It's quite in your face in the area, on the estates," explained the 34-year-old. "We have a huge number of youth, too, so it probably seems more pronounced than elsewhere." A committed member of the East London Mosque, he talked of overcrowding, underachievement and unemployment all contributing to heroin and crack cocaine use among men and women. Kids are often used as runners by dealers higher up the chain; the gangs here merely the foot soldiers in a wider war.

After meeting Shafi, I take the chance to drive around the estates with Siraj, and to talk with Khalid, his softly spoken colleague - and former gang leader - from the Tower Hamlets' Rapid Response Team. The two are called out to deal with the huge gang problem unfurling across the borough, across its different races; this week's clashes marked in colour on a map in their office. When I last spoke with Khalid, he had to drop the phone to rush out and deal with a shooting. It makes you realise what different worlds the people here inhabit. Perhaps we all do.

For it was just two years ago that I drove the same streets with Dave Hill, the former leader of the East London branch of the far-right British National Party (BNP). A heavy-set, powerful figure, Dave, 35, is well known inside the far right. Our first meeting in the drab surrounds of a Stepney pub - not a mile away from where Siraj lives, and not far from where Sir Oswald Moseley and his blackshirts would gather - took place among half-draped St George's flags and the greying atmosphere of decay. Of something passing away. But Dave was proud of his British heritage: "My family's been 'ere for 250 years."

Expelled from the BNP, he lives alone with his mother and has links to Northern Irish loyalism. He mentions matter-of-factly that he's been in Belfast 15 times. When I ask about the main problem in the East End today, his response is swift: "The Asians. Without a doubt." But this seems a losing battle. The BNP may have had Derek Beackon, a councillor, elected to the Isle of Dogs in 1993 but it was short-lived. People like Dave are a shrinking minority - in east London at least. The drama England Expects asks what might happen if a fictional far-right party wanted to win the area back.

The Poplar streets not far from Dave's home are hostile territory. But for Ish, a charming but slightly eccentric young man of Pakistani origin - who tells me he's a Sufi Muslim and a "social manipulator" - the neo-Nazis are found, not among the old Cockneys, but in the latest arrivals: "The Eastern Block". Making it sound like a turf war is already brewing, Ish claimed East European immigrants and asylum seekers - "Serbians claiming Polish citizenship" - are involved in conflicts with the Bengali gangs, and frequently abuse the locals. "Only they've got guns," he said. "It's a very fascist attitude from the newcomers, like 'you're less than us'. I'm involved in the resistance because the Asian community here doesn't have much faith in the police. Other than that," he added without a hint of irony, "it's one of the most comfortable areas in Europe."

Away from Ish and his charm, out of the bars on Brick Lane, even Siraj agrees with part of this prognosis. He saw three Lithuanian guys, drunk, kicking and abusing Bengali elders outside a shop. "I was really surprised," he said.

Jonathan Myers is not. For him, the area has been changing rapidly since he left in 1979 to live in Israel, ending up fighting a war in foreign lands against Islamic militants. With bags under his brown eyes, Jonathan, 41, is a Sephardic Jew. His family history goes back here hundreds of years, and now he's an outsider. He feels the recent changes are insulting to memory. He said: "Could you imagine calling it Yidsville when it was populated by Jews? Jews have abandoned the East End. Forgotten their routes; changed their accents. I won't." But change is omnipresent here. Who can tell what tomorrow will bring?

Nick Ryan is author of Homeland: Into a World of Hate (Mainstream Publishing) and creative producer of the BBC drama England Expects, showing today from 9pm to 10pm and 10.35pm to 11.35pm on BBC1. www.nickryan.net.