Former Alberta premier Peter Lougheed has died at age 84.

Prime Minister Stephen Harper's office confirmed that Lougheed died Thursday in the Calgary hospital bearing his name.

His illness was not disclosed.

The Calgary lawyer toppled the long-governing Social Credit in 1971 and would lead the Progressive Conservatives until 1985, building a dynasty that has been in power for more than 40 years.

He thrust Alberta onto the national station as he transformed the province into an economic powerhouse and battled the federal government over control of oil wealth.

He was immensely popular with voters who gave the Tories ever-larger majorities as they reshaped Alberta into a force in Canadian politics.

This summer, Lougheed was named the best Canadian premier of the last 40 years by the Institute for Research on Public Policy.

(Canadian Press)