Supporters of Liberal Party leader Justin Trudeau cheer at his election night headquarters during Canada's federal election in Montreal, Quebec, October 19, 2015. [Photo/Agencies]

A former teacher and snowboard instructor, Trudeau was first elected as an MP in 2008. He won again in 2011, but the Liberal party suffered its worst election showing ever. After the party leader resigned, Trudeau's name began to be floated around as the next chief.

Trudeau, who has three children, initially said he was undecided due to his young family but eventually reconsidered and won the leadership election by a wide margin.

Support for the Liberals surged after his win but that goodwill had evaporated by the time the election got underway in August.

The tone was set by an early Conservative attack ad that claimed Trudeau wasn't ready to be the country's next prime minister and took aim at his looks with the comment, "Nice hair, though."

"What Trudeau did was surprise the field, and he stiffened the spine of a lot of liberals who were wavering," said Nelson Wiseman, a political scientist at the University of Toronto.

Trudeau also touted a path for Canada that he said was more ambitious than his opponents'. His slogan "Real Change" echoes Barack Obama's successful "Hope and Change," and Trudeau admires how, in his view, Obama transformed grassroots democracy.

Trudeau's short political career has not been without its gaffes.

Critics say Trudeau's comments and headline-grabbing events, such as challenging a Conservative senator to a televised boxing match and winning in 2012, lack gravitas. After Canada joined the coalition against Islamic State, he said humanitarian aid was better than "trying to whip out our (fighter jets) and show them how big they are".

While his rise in politics may appear to have been swift, former interim Liberal party leader Bob Rae said Trudeau has been thinking about it much longer.

"From the time I met him, my sense was that he very much saw this as a long game for him. And one that only had one conclusion."