The French founders of Montreal and the Indigenous people who inhabited the island before their arrival were honoured as part of a full day of events marking the city's 375th anniversary celebrations.
"I think it's a great moment that we are living today, because we always put forward the idea of living together," Mayor Denis Coderre said Wednesday.
"We started with the French, with the Indigenous people. We have our flag that represents the English, the Irish and the Scottish, then all that wonderful diversity that sends a strong message that living together is part of our DNA."
Coderre was joined by Prime Minister Justin Trudeau and Quebec Premier Philippe Couillard at a ceremony paying tribute to the city's founders, Jeanne Mance and Paul Chomedey de Maisonneuve.
The city was founded on this day in 1642, when the missionaries led settlers onto the island.
Mohawk dancers and singers took part in festivities on a sunny day in Old Montreal, as did dancers from École supérieure de ballet du Québec.
Earlier, church bells rang out across the city ahead of a mass at the Notre-Dame Basilica.
The Fort of Ville-Marie, the birthplace of Montreal, was also inaugurated at the Pointe-à-Callière Museum as part of the celebrations. Artifacts uncovered by archeologists over the last 25 years were also unveiled to the public for the first time.
Protests, high costs and questions
Coderre has made the birthday celebrations a priority during his time in office, pouring millions into projects in anticipation of this year's anniversary — which also happens to be an election year.
Some of the projects have been subject to controversy, including the lighting of the Jacques Cartier Bridge at a cost of nearly $40 million, most of which is public money.
The bridge will be lit up for the first time tonight.
According to calculations by Radio-Canada, the full list of festivities and projects will cost more than $1 billion.
As part of the celebrations, Montrealers can use the public transit system for free all day on Wednesday.
Thousands march in protest
There were protests Wednesday as well. More than 2,000 off-duty police officers marched to city hall in Old Montreal, blaring music and holding signs referring to Montreal Mayor Denis Coderre as "a clown."
Police have been without a contract since Dec. 31, 2014.
Meanwhile, affordable housing activists took to the streets Wednesday morning, and another protest targeted the city bylaws dealing with horse-drawn calèches, pit bull-type dogs and other animal control issues.
The celebrations have prompted debate among First Nations, who point out that Montreal was founded on unceded Mohawk territory.
- 3 Mohawks reflect on Montreal's anniversary
- Lights, music, action: Jacques Cartier Bridge to be illuminated for 1st time tonight
Coderre has repeatedly acknowledged in his remarks that Montreal was founded on Mohawk land.
On Wednesday, he stressed that "it's important to remember who we are and where we are coming from," adding that he's hopeful the festivities will help contribute to reconciliation.
"We have a duty to remember and recognize the Native people, who've also suffered over the centuries of this grand European migration and who have contributed to the edification of society that we live in and who continue to contribute today," he said.
Trudeau praises 'world-class city'
Trudeau told reporters his birthday wish for Montreal, which was known as Ville-Marie when it was founded on May 17, 1642, is another 375 years of diversity, pride and openness.
He said he is a proud Montrealer even though he was born in Ottawa, calling Montreal an "extraordinary, world-class city."
"This is an opportunity to be here both as a prime minister and an incredibly proud Montrealer," he said.
Couillard echoed those words of praise, calling Montreal a "city of diversity, with beautiful projects, attracting people from all over the world to put down roots and chase their dreams.''
"We feel a new energy, lots of creativity, lots of economic activity and enthusiasm in Montreal now for the future. I think the founders would be very proud of what Montreal and Quebec have become," he said.
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