Condolences are pouring in from across Canada following the news that Alberta's former premier Peter Lougheed died Thursday evening.

Lougheed, 84, is being remembered as a man who left an indelible mark on Alberta and the country.

Albertans will have an opportunity to pay tribute to Lougheed as the Alberta government announced Friday afternoon that he will lie in state in the rotunda of the legislature in Edmonton from 10:30 a.m to 8 p.m. MT Monday, and 8 a.m. to 8 p.m. on Tuesday.

Prime Minister Stephen Harper said Lougheed was a driving force behind the province’s economic diversification.

“Today Canada lost a truly great man. Peter Lougheed was quite simply one of the most remarkable Canadians of his generation," the prime minister said.

Harper pointed to Lougheed's work to maintain greater control of Alberta's natural resources and their development, raise the province's profile in the confederation, and improve the province’s health, research and recreational facilities.

"Obviously [I] miss him as ... an advisor that I greatly respected," he said.

"I can't say enough about what he has contributed and it's just one of those times where it really makes you sit back and look at the great sweep of history and what has been achieved and in particular, to admire Peter Lougheed's role in all of that."

Lougheed became premier in 1971 when he swept the Social Credit Party out of power.

Premier reacts from Asia

Alberta Premier Alison Redford said she is deeply saddened by the news of former premier Peter Lougheed's death, who she called a powerful role model. (Jeff McIntosh/Canadian Press)

“I am deeply saddened by the death of my dear friend and mentor, Peter Lougheed," Alberta Premier Alison Redford said in a statement issued from a trade mission in Asia.

"He was a powerful inspiration to me. He was a role model and mentor for me both personally and professionally since I first met him many years ago."

Redford's office announced Friday that she will be cutting her trip short and returning to Alberta.

“Premier Lougheed was unquestionably devoted to Alberta and Alberta’s interests. He not only believed in a strong and united Canada, he believed that Alberta did not have to succeed at the expense of Canada, but as a proud member of a country working together — a country where all succeeded."

Alberta Opposition Leader Danielle Smith said he was a man of great personal integrity.

“My thoughts are with the Lougheed family, especially his wife Jeanne and his four children Stephen, Andrea, Pamela and Joseph, as they go through this difficult time of grieving and loss," the Wildrose Party leader said.

“Mr. Lougheed will be fondly remembered as a man who fought on behalf of all Albertans with tremendous dignity and effectiveness during the days of the National Energy Program, and who developed the Heritage Savings Trust Fund for future generations to enjoy the wealth of our abundant non-renewable resources."

Lougheed had been ill for a long time, but he continued to speak out publicly, including his opposition to the Keystone pipeline proposal and support for Redford during her campaign to become premier.

Tough, but a gentleman

In an interview Friday morning from his home in Shawinigan, Que., former prime minister Jean Chrétien hailed Lougheed as a "real gentleman."

"He was a tough guy, in a way," Chrétien said of his contemporary and sometimes political adversary during Canada's constitutional negotiations in the early 1980s, who became his colleague at the same law firm, Bennett Jones, later on in their careers.

Lougheed "had his views [and] expressed them well," said Chrétien, who served as Pierre Trudeau's justice minister during the patriation of the Constitution in 1982.

"And he was tough, but he was a gentleman. We could disagree with him and there would never be bad blood between us. And we agreed on many things."

The family of former premier Ralph Klein said Lougheed could always be counted on to provide advice and guidance to others.

“I can only speak to his kindness and to the personal relationship he shared with my husband,” Colleen Klein wrote in a statement on behalf of her husband, who has dementia.

“Ralph, like all Albertans, understood how Peter Lougheed put Alberta on the global map, so that others, like Ralph, could follow.”

Full of integrity

"I always respected his integrity, his way of doing things — just his mannerism and the thoughtfulness he had for individuals," said Bill Purdie, who served as an MLA in the province from 1971 to 1986.

Lee Richardson, who knew Peter Lougheed for 45 years, said he was a great family man. (Lee Richardson's website)

Marvin Moore, a former Alberta cabinet minister, worked under Lougheed.

"He was a great leader and put Alberta on the map in a number of different ways,” he said.

“And one of the things he isn't recognized so much for is that he had a very good social conscience. He always wanted to do the right thing for social services and health care, and a lot of people don't recognize that, but it was one of his strong points."

Lee Richardson, a former Conservative MP who worked in Lougheed's office from 1974 to 1983 and who knew him for 45 years, said of "all the great things that Peter was, he was a great father and husband and friend to us all."

Provincial NDP Leader Brian Mason said his thoughts are with Lougheed’s family.

“The work that Peter Lougheed did to make Alberta better is recognized by people from across the political spectrum and across Canada,” he said.

Federal NDP Leader Tom Mulcair said Lougheed’s work and achievements "for Albertans and all Canadians has left an indelible mark in our collective history and will be remembered by future generations."

Remembered for his hard work

Calgary Mayor Naheed Nenshi said Peter Lougheed made a better Alberta and Canada. (CBC)

“His work to ensure that Albertans get a fair deal for their resources, to create a more progressive province, to improve our education system and to encourage a fairer society is of unquestionable importance to the province that we have today.”

David King, a former provincial education minister, volunteered with Lougheed as a young man and later worked for him.

"He loved Calgary, he loved Alberta and he loved Canada. I think that showed up time and time again in the things that he did," King said. "He was inclusive, he didn't exclude people."

Calgary Mayor Naheed Nenshi said "I, like every Albertan of my generation, am a Lougheed baby.

“I was born the year after he was first elected, and I have never known an Alberta or a Canadian that did not benefit from his legacy. We owe him so much: our strong industries, our magnetic cities, our sense of identity within Canada.”

Nenshi said Lougheed represented the Alberta that drew so many, including his parents, to live, work and thrive in the province.

“With him, we became greater as Albertans and as Canadians,” Nenshi said. “On behalf of all the people of Calgary, I express my heartfelt sorrow to Jeanne and the entire Lougheed family. He will be dearly missed by all.”