There are an estimated five million Muslims in France today, which is the largest such population in Western Europe.

A century ago, they were called "colonials"; in the 1960s, they were known as "immigrants"; today, they are "citizens".

With issues of immigration and integration raising the political temperature in Europe, this three-part series looks back at the history of Muslim immigration into France. It is a history that remains alive today, with the ongoing debate over how to reconcile France's long-standing tradition of secularism with religious diversity.

What challenges have Muslim immigrants in France faced and overcome in order to retain their cultural identity in a foreign country?

In 1904, 5,000 Muslims were working in mainland France on shop floors in Paris, in Marseille soap factories, or in the northern coalfields. They were called "Kabyles" as most of them came from Kabylia in northern Algeria.

"They live like all the French workers. They move to a city, for example Lille in the North of France. The first thing they do, it seems, is abandon their traditional costume, some even wear a beret. They adopt the codes of the workers' movement," historian Linda Amiri says.

Back then, no one imagined these workers, brought from North Africa, would stay in France to raise their children and grandchildren.

In the First World War, France recruited massively from the colonies and hundreds of thousands of soldiers from North Africa and Black Africa set sail for the battlefields. The price paid by the Muslim troops from Africa was heavy.

After the war, the colonial soldiers returned home, but France had to be rebuilt. Some North African workers stayed on, going from the arms factories to major public works. Thousands of others joined them. They came mostly from rural Algeria. Soon, the ranks of these Muslim workers increased to 100,000.

"They lived in great poverty, that means that they are people who came to France but didn't come to stay, who they came, in fact, solely for work. It's a life of labour and sacrifice: they work all the time, they make money and send everything home," says sociologist Ahmed Boubeker.

In 1923, the press made the most of a gruesome story. An Algerian murdered a shopkeeper who refused his advances, as well as one of her customers. The newspapers dubbed the crime the Double Murder of the Rue Fondary.

Despite the following monitoring and repression of Muslims in France life went on. Between Muslims and French there were dates, romance, and marriage became more frequent.

During the Second World War, 15,000 Muslims lived in Paris, and like all the French the Muslims were faced with a choice: To resist, to collaborate or to keep a low profile - a personal choice influenced by their pre-war political allegiance.

In late August 1944, Paris was liberated, in part thanks to the sacrifice of 3,000 resistance fighters. How many among them were Muslims? We will never know. They were born as North Africans - and they gave their lives for France. But post-war France was to care little for their sacrifice.

Colonials airs from November 29, at the following times GMT: Tuesday: 2000; Wednesday: 1200; Thursday: 0100; Friday: 0600; Saturday: 2000; Sunday: 1200; Monday: 0100; Tuesday: 0600.

After 1950, the families of Muslim workers started to follow come to France, creating a new generation of Muslims growing up in France [GALLO/GETTY]

By 1945, Muslim natives had been working in France for 40 years. Most of them had come from Algeria. In the inter-war period, around 100,000 arrived to stay for a few months, or a few years at the most, with the certainty of one day returning home. In the aftermath of the Second World War, all that changed.

"From the 1920s to 1950s, we have 30 years of worker immigration, but not family immigration. The immigrants are alone. This is a central question because men alone have the possibility of returning home. But when you have children, when a family emigrates, there's no more returning. It's no longer the same situation. When the children arrive, the wife arrives, they settle in a small apartment, the children go to school, others are born in France, it's the beginning of another story," says historian Benjamin Stora.

The vast majority of Muslims living in France were still Algerian nationals. Families were growing and the numbers of children of workers from the Maghreb increased in French schools. There, they discovered a different culture from their parents' - a culture they often took naturally. And North African parents wondered how to pass on their customs to children growing up in a non-Muslim country. 

Growing up in France at that time meant seeing racist crimes on evening news. The most deadly outburst came in 1973 in Marseille. Twelve Arabs were killed in a few days.

A major strike movement began in the SONACOTRA hostels with North Africans and Africans living there making a united stand against poor lodging conditions. Unions and left-wing parties united behind the immigrants' demands. But in a period of soaring unemployment, the state was tempted quite simply to send all foreigners back home.

In 1977, President Valery Giscard d'Estaing launched an assisted repatriation scheme. Objective: 500,000 departures. The Algerians were the main target. But children who had grown up in France would not be shown the door so easily.

The repatriation scheme only affected a small number of people, though it worried many more. The children of Algerian, Moroccan and Tunisian workers carried on growing up in France.

This generation of Muslims in France were still called immigrants. And yet, unlike their parents who continued to dream of returning to their homeland, they knew their future was in France and just wanted to get on with their lives without being harassed by the police. France did not notice them growing up, but soon it would learn to reckon with them.

Immigrants airs from December 6, at the following times GMT: Tuesday: 2000; Wednesday: 1200; Thursday: 0100; Friday: 0600; Saturday: 2000; Sunday: 1200; Monday: 0100; Tuesday: 0600.

In April 2011, France became the first European country to enforce a ban of the face veil in public, which is just one of the many issues that emphasise the schism that remains between the different faces of French society [GALLO/GETTY]

By 1981, Muslims had been working in France for some 75 years. Their children had grown up in the French system at school and with the culture of their motherland at home.

They were entering adulthood at a time when the years of economic crisis had resulted in massive unemployment in the government housing estates, now a crucible of social problems. So much so that a part of the immigrants preferred to leave.

But on July 10, 1981, riots broke out. Called Les Minguettes rodeos, kids raced around the estate in stolen cars which they later set on fire. France suddenly woke up to the malaise of the suburbs.

"The ones who burn cars are the children of immigrant workers. And we realise that these immigrants have had children. Surprising, I know, but we didn't realise before that this immigration had taken on a family dimension and that there were descendants of immigrants who were, in fact, French. We begin wondering about this generation when the riots begin. The riots are this generation's birth certificate. They refuse to be treated like their parents' generation and demand their place in France," sociologist Ahmed Boubeker says.

While these young Arabs who had grown up in France wanted to share their mixed culture with the rest of the country, their fathers worked in the factory. Mostly they were unskilled workers at the very bottom of the ladder. In spring 1982, a series of strikes hit the Talbot, Citroen and Simca factories in the Paris area. Factories where Arab and Black workers were often in the majority. They called for better work conditions and freedom for unions. 

The government saw no way out of this endless social dispute and accused the strikers of being manipulated by Iranian fundamentalists. The accusations were repeated in the media and this view, which painted a picture of a France in danger of Islamisation, would keep resurfacing from here on. But at this time, the danger was to young North Africans racism and violence.

In the nineteen-eighties, integration into French society was still a rocky path for the children of North African immigrants. Throughout France, many young people seemed to be rediscovering their Islamic identity. This religious revival was also beginning to attract a certain number of non-Muslims.

Those who renounced Islam did so quietly. It was those who trumpeted their allegiance to Islam who attracted media attention. When schools restarted in September 1989, three young girls were suspended from their high school in Creil for refusing to take off their headscarfs inside the school building. So began the affair of the veil.

The matter of the veil continues to be contentious until today. In April 2011, France became the first European country to enforce a ban of the face veil in public, just one of the many issues that emphasise the schism that remains between the different faces of French society. The term French Muslims is both paradoxical and simplistic, but one that marks out those heirs to a particular history within the wider history of the French nation, those who came to build and defend France with little recognition. It means together creating a new country where, through confrontation and conjugation, we learn to shake off our hidebound identities.

Citizens airs from December 13, at the following times GMT: Tuesday: 2000; Wednesday: 1200; Thursday: 0100; Friday: 0600; Saturday: 2000; Sunday: 1200; Monday: 0100; Tuesday: 0600.