It's known as La Main - "The Main" - and it's the lifeblood of Montreal.

For the past three centuries this sweeping avenue, Boulevard St Laurent, has shaped the character of a city in the heart of French-speaking Canada.

La Main was once the symbolic dividing line between the city's French and English speaking communities, with the boulevard a soft buffer attracting and absorbing waves of new immigrants.

Today, it celebrates a cosmopolitan city with its array of little villages, from the Quartier Chinois, or Chinese quarter, to Little Italy and Portugal, along with strong remnants of an historic Jewish quarter.

'Essentially French'

But French-only street signs draw the line on Montreal's mosaic. Even the famous Schwartz's delicatessen, where tourists queue daily for its popular Montreal Smoked Meat, is 'Charcuterie Hebraique de Montreal'.

"This place is changing, changing quite a bit," reflects Montreal radio host Mike Finnerty. "Francophones say that they want to make sure it remains essentially a French-speaking city but it is also a bi-lingual city. It almost always has been since it's been settled."

In the studios of the Canadian Broadcasting Corporation (CBC), Mike's Daybreak Montreal programme in English sits right next to a breakfast programme for Montrealers who start the day in French.

The day we drop by, the province's more than three-month-old student unrest over tuition fees is still making headlines. Some are calling it a "Maple Revolution" in defence of Quebec's spirit of social solidarity.

Lobster poutine is the speciality of The Larder

Built on a large island with connecting smaller islands in the middle of the mighty St Lawrence River, the city is defined by Mount Royal, the triple-peaked hill which gave the settlement its name.

Montreal has scaled the heights of excellence in many fields since then, earning it the title of Canada's cultural capital. It has given the world its circus sensation Cirque du Soleil, music superstars such as Arcade Fire and Leonard Cohen, and literary successes like Mordecai Richler. And if you haven't yet gone in search of a Montreal bagel, you don't know your bagels.

Sugar Sammy is one of its new rising stars as well as a poster boy for the province's famously strict language laws.

The Montreal-born comedian takes on the prickly cultural issues in his sold-out performances where he moves seamlessly from English to French, to Hindi and Punjabi. He's held on to the ancestry of his Indian parents who moved to Quebec and had to put their children in French language schools because of Bill 101.

This Charter of the French Language mandates the use of French everywhere from street signs, shops, and in schools.

"I grew up here, absorbing all the cultures, the languages, and really being open-minded," he says.

As we browse the racks in an elegant men's clothing store in Vieux Montreal (Old Montreal), I ask what he's looking for. "Something that's Montreal style which is an influence of pretty much everywhere. It's a little bit North American, a little bit European, mixed together."

The shop's interior is sleek and minimal, and it sits on a cobbled street of historic stone mansions in an area recalling the era when French and British imperial powers vied for influence.

Calorific creation

Just down the street, another Montreal star is adding a modern touch to another Quebec classic.

At Garde Manger (The Larder) celebrity chef Chuck Hughes stirs a huge cauldron of the silky lobster sauce that put poutine, Quebec's favourite fast food, on the top tables.

The traditional caloric mound of fries, cheese curd, and brown gravy has been transformed by his rich sauce and moist morsels of lobster into Lobster Poutine.

It recently won him the coveted American 'Iron Chef' title, making him the first Quebec chef to triumph in the epic cooking battle.

"I don't want to be just known for my fries," he quips as he flits around his steaming kitchen in black baseball cap and shirt, his self-deprecating banter and cooking prowess both in full flow.

'On the map'

Montreal is known for many things including the 1976 Summer Olympics that cost the city a fortune. The sloping tower of the Olympic Stadium protruding from the city's skyline is an awkward reminder of what came to be known as the 'Big O' - not for Olympics but the huge debt of $2bn (£1.25bn) they owed for the privilege of hosting them.

Olympic swimmer Dick Pound defends its legacy, insisting the Games "put Montreal on the map". A long standing member of the International Olympic Committee, and "passionate Montrealer" he says the Games were an investment that paid off.

At the Rowing Basin, one of the few venues still in use, some young women rowers are adamant they couldn't have excelled without this Olympic legacy. As they take to the water, they reveal they're actually the World Dragon Champions.

Some things about Montreal may be priceless, including that "joie de vivre" - the joy of living in a world-class city with an identity all its own.

WATCH: Montreal is a French island in a predominantly English-speaking country: 

http://www.bbc.co.uk/news/world-radio-and-tv-18105651