Alberta’s former premier Peter Lougheed, considered by many to be one of Canada's best premiers, died Thursday night at the age of 84.

“It is with great sadness that the family of The Honourable E. Peter Lougheed, the tenth Premier of the Province of Alberta, announce that he passed away peacefully today from natural causes in Calgary, Alberta,” said a statement from Lougheed's family issued Thursday night.

Lougheed was reported to be in hospital earlier this week, being treated for an undisclosed illness.

In a statement, his family thanked members of Alberta Health Services, “who have helped care for him over the last months and days.”

His family said he died in hospital peacefully of natural causes.

"Although he was known to many for his contributions to Alberta and to Canada, his first dedication was to his family. He was a deeply caring and loving husband, father and grandfather. We will miss him terribly."

Lougheed was born and raised in Calgary and served for 14 years as Premier of Alberta – from 1971 to 1985.

He was the province’s tenth premier and has lived in both Calgary and Edmonton with his wife, where they have raised four children.

Politicians expressed their condolences after news of Lougheed's death broke - many remembering Lougheed as an icon of Alberta.

Premier Alison Redford - who was travelling on a trade mission in Asia - said in a statement that she was "deeply saddened by the death of (her) dear friend and mentor."

"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 said.

"He created a direction for Alberta that we can all be proud of today. His forward-thinking, progressive vision gave us the tools to succeed today and helped to propel Alberta into a leadership role in Canada."

House speaker Gene Zwozdesky, speaking to CTV News from Sri Lanka, said he was "very, very saddened."

"He was a great friend, statesman and icon of Alberta," Zwzodesky said.

Zwozdesky had worked with Lougheed in the '70s. He expressed his sympathies to Lougheed's family and praised Lougheed’s legacy, which includes his role in the creation of the Alberta Bill of Rights, the Alberta Heritage Savings Trust Fund, which used natural resource royalties to fund infrastructure projects and services, and Lougheed’s contribution to language, arts and culture.

“On all occasions he spoke with passion and persuasion on behalf of the citizens of our great province," Zwozdesky said.

Prime Minister Stephen Harper called Lougheed "one of the most remarkable Canadians of his generation."

“Today Canada lost a truly great man," Harper said in a statement.

"Peter Lougheed was quite simply one of the most remarkable Canadians of his generation. A master politician, gifted lawyer, professional-calibre athlete and philanthropist, the former premier was instrumental in laying the foundation for the robust economic success that his cherished province of Alberta enjoys today."

Politicians from near and far reacted to the news.

Former Alberta premier Don Getty handpicked Lougheed to join his team.

"He had a desire to do big things for Alberta," Getty said.

"We worked as hard as possible to make Alberta great because he was our leader."

Former Newfoundland premier Brian Peckford remembered how Lougheed helped his province through the creation of a fund to help provinces accses low interest loans.

"He didn't have to support Newfoundland like he did but he did," Peckford said.

"We are eternally grateful for that."

"It is with tremendous sadness that we bid adieu to a giant of Canadian politics," MP Justin Trudeau posted on Twitter. "Peter Lougheed was a man of vision, integrity and heart."

"Condolences with the passing of former Alberta Premier Peter Lougheed," wrote MP Tony Clement. "A political giant, but took the time to be kind to me."

This year in June, Lougheed was chosen as the best premier in the last 40 years by the Institute for Research on Public Policy. He accepted the award at a ceremony in Calgary – his last major public appearance.

The win is largely credited to his battle with the federal government and Pierre Trudeau.

Lougheed fought for equal treatment of all provinces and against the federal government's energy strategy.

Lougheed was a lawyer before he entered politics. His run as Premier started by defeating the Social Credit in 1971. It was the first change in government in the province in 36 years. Loughheed's Progressive Conservatives won 49 seats.

Lougheed was student union president at his Calgary high school. He also studied at the University of Alberta - where he played football for the Golden Bears.

"In my view, Peter Lougheed is a giant among U of A's thousands of extraordinary alumni. His leadership on campus as a student foreshadowed the leadership he would display throughout his life," wrote University of Alberta President Indira Samarasekera.

"His dedication to public service, in politics and beyond, will always remain a powerful model for all current and future U of A students who strive, as he once did, to be a leader and a force for positiev change within society."

Lougheed also won a Grey Cup during his time with the Edmonton Eskimos.

He has received many honours for his life work, including seven honourary degrees, receipt of the Harvard Business School Alumni Achievement Award, induction into the Canadian Medical Hall of Fame and the Canadian Olympic Hall of Fame.

Lougheed and his wife were also named honourary fellows of the Banff Centre and the Royal Conservatory of Music.

A number of endowments, parks and facilities bear his name.

He supported the development of Alberta’s controversial oilsands and famously fought with then-Prime Minister Pierre Trudeau over the National Energy Program, which Albertans saw as an intrusion in their province’s affairs.

He resigned as Premier of Alberta and MLA for Calgary West on February 28, 1986 and returned to the private sector.

He was appointed as a member of the Privy Council of Canada in 1982 by Her Majesty The Queen and in 1987, he was appointed a Companion of the Order of Canada.

In his later years, he was a partner in the Calgary law firm of Bennett Jones LLP and served on numerous Boards of Directors.

He is called the 'Father of Modern Day Alberta' and the architect of the province.

In Lougheed's last interview with CTV Edmonton, he said he hoped voter apathy would turn and more people would become politically active.

He added his voice to the recent election, throwing his support behind Alison Redford.

Lougheed is survived by his wife, four children and seven grandchildren. His family will celebrate his life in a private service.

Plans for a public memorial will be announced in the coming days.

"In lieu of flowers, any donations or volunteer actions that support his charitable interests would continue to fulfill his hopes and vision for Alberta and Canada," the family statement read.

The province also announced on Friday that Lougheed will be lying-in-state in the rotunda of the Alberta Legislature in Edmonton from 10:30 a.m to 8 p.m. Monday, Sept. 17 and 8 a.m. to 6 p.m. on Tuesday, Sept. 18.

Books of condolence will also be available for members of the public to sign in the rotunda.