What makes a great PM? Trudeau biographers weigh in

After befriending Pierre Trudeau, Max and Monique Nemni were given access to the former prime minister's archives: journals, agendas and scraps of paper the politician used to jot down his thoughts throughout his life.

What emerged, the husband and wife say, is a version of Mr. Trudeau that no one knew before. The Nemnis documented the early years of his life in their first book, focusing on his intellectual development. The second volume, Trudeau Transformed: The Shaping of a Statesman 1944-1965, is one of five finalists for the Shaughnessy Cohen Prize for Political Writing. Their first volume, Young Trudeau: 1919-1944 Son of Quebec, Father of Canada, won the prize in 2006.

The $25,000 award for non-fiction is administered by the Writers' Trust of Canada and named after Ms. Cohen, a late outspoken Liberal MP from Windsor, Ont. The prize will be handed out on Wednesday evening at Politics and the Pen, an annual gala popular among Ottawa's politicians and journalists.

Ahead of the prize, The Globe asked Mr. Nemni about the former prime minister.

What's the most surprising thing about Mr. Trudeau?

The most surprising thing, we described in our first book, was that everyone thought that Trudeau was a Liberal from the day he was born. When we researched those early years, we discovered this wasn't the case at all. We had a completely different Trudeau than anyone expected, one who wanted a separate a Quebec. In the second volume, what we see is a man being transformed, which reveals things that weren't known. He is usually described, in this period that we're covering (1944-1965) more or less he was a playboy around the world. But in fact he was very, very involved in all kinds of political activities, union movements and trying to educate people about democracy.

What was a defining moment of his career?

When he got out of Quebec, went to study at Harvard, then Paris, then London and then around the world. He wanted to really understand properly the world and that was a defining moment in the sense that he was transformed there. He had a certain set of values that he had acquired in Quebec and he looked at the world in a completely different way when he got out of Quebec to look at the world and try to understand it. He was really ready to listen to people ... This allowed him to get away from some of the cultural values that he acquired in Quebec. He came back wanting to fight to improve.

What makes a great prime minister and has it changed since Mr. Trudeau's days?

One of the most important things about Trudeau is that he was a person dedicated to the common good. He didn't particularly like politics, he wasn't a politician per say, he wasn't a person who loved to delve into political life. But he knew that politics was an absolutely essential instrument in order to transform society and to do good. A good statesman to me is one who is concerned with the common good rather than having a political life. I think that from the day of Plato, until forever, this is the definition of what a good leader.

What would he say about politics today?

After he was out of politics, for many years he didn't say anything. He thought it wasn't his business to comment, he only came back and very forcefully when he thought that the government of Brian Mulroney was acting in a dangerous way with the Meech Lake accord and Charlottetown Accord. To him, that was a way of breaking Canada by distributing powers widely to the provinces. In other words, I don't think he would really come back and say anything today.

This interview has been edited and condensed