Speaker of the House of Commons Geoff Regan speaks for the 150th anniversary of the first meeting of the first Parliament of Canada as leaders rise to deliver statements in the House of Commons on Parliament Hill, in Ottawa on Monday, Nov. 6, 2017. THE CANADIAN PRESS/Sean Kilpatrick

OTTAWA - Moments from Canada's colourful — and sometimes dark — past came back into focus Monday as federal politicians and former prime ministers of all partisan stripes gathered in the House of Commons to mark the 150th anniversary of Canada's first Parliament.

House of Commons Speaker Geoff Regan encouraged current members of Parliament to imagine what it was like on Nov. 6, 1867, when the country's first lawmakers gathered in Ottawa.

"Imagine the enormity of the task before these first parliamentarians ... facing the monumental challenge of governing a vast and sprawling country still in its infancy," Regan told the Commons.

"Any democracy worthy of its name is always a work in progress, and it is our duty as parliamentarians to build on the foundations laid by those first members of Parliament who established the country that it is our privilege to serve."

Prime Minister Justin Trudeau reminded former and current parliamentarians of several noted events since that time — both good and bad — that have shaped Canada into what it is today.

"Within these walls, Canada has been reborn countless times," Trudeau said as he recalled how previous governments made strides in human rights, introduced universal health care, abolished the death penalty and gave same-sex couples the right to marry.

The prime minister also acknowledged some "dark and shameful moments" in Canada's history, such as the introduction of the residential schools program that aimed to assimilate Canada's Indigenous Peoples.

"Let us be women and men of principle and of humility, for we have been bestowed the responsibility to serve and we must do so honourably," Trudeau said.

"Let's never lose sight of the fact that we're all here for the same reason, to make our country better, to improve the lives of the people were serve. We may have different ideas on how to get there, but there is always common ground — and if we work together, we will find it."

Conservative Leader Andrew Scheer called the Parliament of Canada much more than merely bricks and mortar. And while Scheer also acknowledged some dark moments in Canada's past, he said there were more good moments than bad over the last 150 years, culminating in a country that is the envy of the world.

"That we who have been entrusted with the governance of Canada have sometimes failed should not be surprising," said Scheer.

"This chamber may be made of wood and stone but the men and women who give it its life are hewn from the crooked timber of humanity.... These chairs have supported patriots and heroes, but also a few rogues."

Former prime ministers John Turner, Joe Clark, Brian Mulroney and Paul Martin were among those who watched and listened from the Commons visitor's gallery as tributes were read into the official record to mark the anniversary. Earlier in the day, the four men sat together and shared a few memories with Regan and former Commons speakers as they celebrated the moment.

"This room is not about us as members of Parliament; this room is about democracy, it is about Canada," said Green party Leader Elizabeth May. "We are very tiny in this space because our role is to represent something far bigger than ourselves. We are here for Canada."

News from © The Canadian Press, 2017