MONTREAL -- Tributes poured in for the late Paul Desmarais on Tuesday at a commemorative ceremony headlined by a veritable who's who of public figures past and present.

Four Canadian prime ministers, a former French president and five Quebec premiers were among those who attended a two-hour memorial for the business tycoon at Montreal's Notre-Dame Basilica. He died Oct. 8 at the age of 86.

Prime Minister Stephen Harper and two of his predecessors, Jean Chretien and Brian Mulroney, delivered eulogies for a man described as both a business titan and a humble, giving friend.

Mulroney, a longtime friend, recalled an exchange he observed years ago between Desmarais and a couple of the businessman's employees at his estate in Quebec's Charlevoix region.

Only a few days earlier, Mulroney and Desmarais had eaten dinner together with the Queen at 24 Sussex Drive.

"I saw Paul seated on the porch with...two of his most trusted workers," Mulroney told hundreds of people who had packed the Basilica pews for the ceremony.

"They were talking about plans for a new garage and a new road for access to the property. I was listening to their conversation on that morning... when something struck me.

"I realized that Paul was interacting with the workers exactly the same way he had with Her Majesty. He was the same man: warm, funny, respectful and direct."

Desmarais, a native of Sudbury, Ont., took over a near-bankrupt family bus operation and eventually built a multibillion-dollar business empire. Over the years, he cultivated political connections on different continents.

Tuesday's crowd of political and business heavywieghts also included Quebec Premier Pauline Marois and her predecessors Daniel Johnson, Lucien Bouchard, Bernard Landry and Jean Charest.

Also present were former prime minister Paul Martin, ex-media mogul Conrad Black, former Bombardier president Laurent Beaudoin, ex-Bloc Quebecois leader Gilles Duceppe, former federal Liberal leader Bob Rae and his successor, Justin Trudeau.

In his eulogy, Harper praised Desmarais as a canny entrepreneur who saw opportunity within Canada and abroad.

"He foresaw the rise of China as a great trading nation and got there long before others," the prime minister said in a five-minute address.

"He understood early the transformation brought about by the unity of Europe and the role it would play in Canada's economic future, a potential now being realized in no small part thanks to the trailblazing efforts of Paul and his connections and those he inspired."

Harper expressed his admiration for Desmarais and called him a humble, generous and unpretentious man.

"He never once raised personal business interests with me," said Harper who also appreciated Desmarais' steadfast belief in Canadian unity.

"Indeed, the one and only common theme of every subject we ever discussed was his country, Canada: its uniqueness, its prosperity, its challenges, its unity."

Testimonials heard Tuesday about Desmarais' life also reminded the audience of his powerful contacts.

Chretien, whose daughter France married Desmarais' son, Andre, recalled how he met with Desmarais after being named parliamentary secretary to then-finance minister Mitchell Sharp in the mid-1960s.

"I told Paul that I didn't know anybody in the big business world," said Chretien, who shared four grandchildren with Desmarais.

"I asked for his help. Forty-eight hours later, we were having lunch with the president of the Royal Bank, Earle McLaughlin. That was Paul Desmarais at his best."

The A-list in attendance on Tuesday also included former French president Nicolas Sarkozy, who has admitted he owed much to Desmarais.

When Desmarais was awarded the French Legion of Honour in 2008, Sarkozy said he was president partly because of the Canadian's advice, friendship and loyalty.

On Tuesday, Sarkozy likened his friend to a tireless fighter and recalled how incredibly sad he was when Andre Desmarais told him of his father's death.

"It was over," he said in a eulogy. "We'd never speak again."

"My dear Jackie (Jacqueline Maranger, Desmarais' widow), not a day has gone by since that I haven't thought about your husband.

"In my life I haven't met too many people with the standing of Paul Desmarais. I will always be proud to say I was his friend."

Desmarais also cultivated high-level friendships at the White House.

The guest list for a Desmarais housewarming party in 2003 included two former U.S. presidents: Bill Clinton and George Bush.

During Tuesday's memorial service, former U.S. secretary of state James Baker read out a statement prepared by Bush.

"Paul was that rarest of men, who possess not only the drive, the integrity and the vision to succeed spectacularly in business, but also a tremendous capacity for friendship," Bush's statement said.

"He was what I would call a true point of light, helping and usually leading many worthwhile causes. So, yes, I liked and I respected this good man immensely. At age 89 and a half, I recognize more than ever the importance and the blessings of friendship."

Baker himself also paid homage to Desmarais, noting how observers have said the businessman had a pipeline into every prime minister's office, regardless of who was in power.

"And you take one look at the list of today's eulogists and I think you see the validity of that comment," said Baker, who described Desmarais as "notre ami."

"Paul Desmarais was a friend, both to Canada and to the United States."

Baker also credited Desmarais for being a capitalist who supported free trade, particularly the Canada-U.S. Free Trade Agreement.

"Yes, Paul Desmarais was proof that what we call the American Dream in my country has been alive and well in Canada," he said.

Desmarais' path to power began in Sudbury, where he was born in 1927. He left law school to take over the family's ailing bus company in 1951.

A series of smart moves resulted in the creation of a holding company that in 1968 made a share-exchange offer with Power Corp.

With his company's diversified holdings in insurance, transportation, paper, media, and financial services, Desmarais was one of the most notable members of his province's business elite, often referred to as Quebec Inc.

His empire included Great West Life, London Life and Canada Life in the insurance industry; the Investors Group and Putnam Investments; the Gesca newspaper chain, with its flagship Montreal La Presse; and stakes in the oil company Total S.A. and the Pernod Ricard liquor company.

He helped open the door to Canadian businesses in China by leading a commercial delegation there in 1978. He was the founding chairman of the Canada China Business Council.

However, it took eight years before Power Corp. launched a business venture there. It now invests in infrastructure projects in China through its stake in CITIC Pacific Ltd.

By the time he handed daily operations of the company to his sons in 1996, Desmarais had seen Power's assets increase to $2.7 billion, from $165 million.

Power Corp., through its Square Victoria Communications Group subsidiary, and together with the corporate parent companies of the Toronto Star and Globe and Mail newspapers, owns The Canadian Press.

Canadian Business magazine ranked Desmarais as the wealthiest Quebecer and Canada's seventh-wealthiest person, with a fortune estimated at $4.4 billion.

Despite his heft in the business world, he was discreet when it came to discussing politics.

Desmarais, however, was a staunch Canadian federalist.

Only on rare occasions did he voice his views publicly. During his last annual meeting as Power's chief executive in 1996, he extolled his belief in Canadian unity.

"My profound attachment to Canada stems from the great liberty and freedom that my ancestors were able to enjoy in building their lives in a new country, the same liberty and freedom which allowed me as a young French-Canadian from Northern Ontario to realize his dream in building a business in all parts of Canada and abroad."

Even with Desmarais' longtime opposition to Quebec's independence movement, he still managed to win the respect of those on the other side of the contentious debate.

"We were totally opposed on many matters -- the national fate of Quebec of course, the management of modern capitalism," former Parti Quebecois premier Landry said after Tuesday's ceremony.

"But for many other things, internationalism, culture, we were on the same floor. And that's why we remained friends."

An art lover, Desmarais had one of Canada's largest private art collections. Two wings of Montreal's Fine Arts Museum are named in honour of his family.

He also had a deep appreciation for music and Montreal's Orchestre Metropolitain performed at Tuesday's service.

Mulroney said while Desmarais was renowned for his skills in business in finance, he was less well-known for his vast knowledge of music, history and architecture.

"Every day with Paul, and I had hundreds with him, both here and around the world -- every one was a good one," Mulroney said.

"Something to learn. Something to do. Some new place to go. Some fascinating people to meet.

"With him, life was a whirlwind of achievements and discussions and debates, laughter, good times and fun."

- With files from Sidhartha Banerjee, Peter Rakobowchuk and Melanie Marquis