TORONTO -- Renowned Canadian political scientist Stephen Clarkson, a leading historian and academic authority on North American relations, has died.

The University of Toronto's political science department, where Clarkson taught for several decades, confirmed he died on Sunday in hospital in Freiburg, Germany.

Clarkson had contracted an influenza virus in Portugal that developed into pneumonia and then an incurable sepsis, the school said. He was in Portugal on a research trip with students.

He was 78.

Clarkson's work focused on areas including the North American Free Trade Agreement and how Canada has been affected by globalization.

In 1990, he and then-wife Christina McCall won the Governor General's Literary Award for non-fiction for "Trudeau and Our Times." The second volume of that book won the J.W. Dafoe prize.

In 2011, Clarkson was named a member of the Order of Canada.

"Stephen was a pillar of the department for many decades," said a Facebook post from U of T's political science department.

"He was a great friend, a most dedicated teacher, and an indefatigable scholar. Our condolences go to Stephen's wife Nora, his daughters, grandchildren and extended family."

Clarkson did his graduate studies at the University of Oxford and the Paris-Sorbonne University. In 1969, he ran for mayor of Toronto.

His other books included "The Big Red Machine: How the Liberal Party Dominates Canadian Politics," "Canada and the Reagan Challenge," and "Uncle Sam and Us."

Clarkson's other honours included an election to the Royal Society of Canada.

He was once married to former governor general Adrienne Clarkson.

"Stephen was devoted to his students, and he saw his teaching as the most important part of his academic life," Louis Pauly, chairman of U of T's department of political science, said in a statement.

"He closely advised generations of undergraduate and graduate students. He held his students to high standards, and they reciprocated with much energy and enthusiasm."

Funeral arrangements have not been announced.