More than 150 years after six B.C. First Nations chiefs were hanged by colonial authorities, Prime Minister Justin Trudeau has apologized and absolved the Tsilhqot'in leaders of any wrongdoing.

"Today, we come together in the presence of the Tsilhqot'in chiefs, to fully acknowledge the actions of past governments, committed against the Tsilhqot'in people, and to express the government of Canada's profound regret for those actions," Trudeau said.

"We honour and recognize six Tsilhqot'in chiefs — men who were treated and tried as criminals in an era where both the colonial government and the legal process did not respect the inherent rights of the Tsilhqot'in people."

In 1864, five Tsilhqot'in chiefs were called to what they thought were peace talks to end what became known as the Chilcotin War.

Instead, they were accused of murdering 14 members of a road-building party. They were then tried, convicted and hanged.

Five of the chiefs were executed, under Crown authority, near the settlement of Quesnel, B.C., in the province's interior. A sixth chief was later hanged near New Westminster, B.C., after trying to offer reparations.

Prime Minister Justin Trudeau offers exoneration and an apology for 6 B.C. First Nations chiefs hanged in 1864. 12:47

The chiefs opposed the construction of roads to gold-rich lands and sought to stop the incursion into their traditional territory.

"As settlers came to the land in the rush for gold, no consideration was given to the needs of the Tsilhqot'in people who were there first. No agreement was made to access their land. No consent was sought," Trudeau said.

The Chilcotin War was also fought in the midst of a disastrous smallpox epidemic which ravaged B.C., wiping out nearly half of all Indigenous peoples in the province in a matter of months. At least 14,000 died in the outbreak and hundreds of others were disfigured, leaving the landscape peppered with mass graves and abandoned settlements.

"Some reliable historical accounts indicate that the Tsilhqot'in had been threatened with the spread of the disease by one of the road workers. And so, faced with these threats, the Tsilhqot'in people took action to defend their territory," Trudeau said.

There are also allegations that the road-building crew violently took some Tsilhqot'in women hostage and subjected them to sexual abuse.

The Tsilhqot'in have long objected to the chiefs being tried as criminals, saying the killing of the colonists was carried out when a state of war existed between the First Nations and the colonial authority in B.C.

Trudeau agreed Monday, saying these six chiefs were "leaders and warriors" of the Tsilhqot'in nation, peoples who maintained their land rights had never been ceded.

The descendants of six Tsilhqot'in Chiefs on the floor of the House of Commons. (Sean Kilpatrick/Canadian Press)

"Even though the colonial government did not recognize these rights, the chiefs acted in accordance with their own laws to defend their territory, their people and their way of life," he said. "They acted as leaders of a proud and independent nation facing a threat from another nation.

"We confirm without reservation that Chief Lhats'as?in, Chief Biyil, Chief Tilaghed, Chief Taqed, Chief Chayses and Chief Ahan are fully exonerated of any crime or wrongdoing."

Six modern-day Tsilhqot'in chiefs were present in the House of Commons for the prime minister's apology Monday. They wore black vests. When Trudeau finished speaking, they stood and turned their vests inside out to reveal their bright red lining — for the Tsilhqot'in Nation, a colour symbolizing rebirth and renewal.

The Tsilhqot'in chiefs then received special permission from MPs to perform a drum ceremony on the floor of the House of Commons.

Six modern day Tsilhqot'in chiefs and a drummer perform a ceremony in the House of Commons recognizing the Prime Minister's exoneration of their ancestors 5:16

Trudeau to visit Tsilhqot'in territory

Trudeau said that while apologies alone can't make right the wrongs of the past, they are an important part of reconciliation and renewing Canada's relationship with Indigenous people.

He said he looks forward to visiting Tsilhqot'in territory this summer at the invitation of the nation's leadership to deliver a statement of exoneration directly to the Tsilhqot'in people.

Joe Alphonse, chief of the Tsilhqot'in National Government, welcomed what he called an apology for the colonial government's "deceitful" actions in arresting and hanging the chiefs.

Tsilhqot'in chiefs scrum in the foyer of the House of Commons after their ancestors are exonerated by Prime Minister Justin Trudeau 9:31

"154 years have passed where our truth has gone unrecognized. Under a flag of truce our chiefs were wrongfully shackled, tried and hanged. We have always been proud of the sacrifices made by our chiefs, who are heroes to our people, and continue to inspire and guide the work of the future," Alphonse said.

"Today, Canada has finally acknowledged that our warriors did no wrong."

Cathy McLeod, the Conservative Indigenous affairs critic, echoed Trudeau's assessment of the chiefs.

"Neither criminals nor aggressors, they did what many of us would consider normal. They defended their homes and their families."

She said the resulting arrest, after the chiefs had made a peace offering, was a "clear act of betrayal."

Guy Caron offered the New Democrats' support for the exoneration and called the apology long overdue. He also called for the creation of a national Indigenous peoples day as a statutory holiday.

"Thank you for your patience with our young country as we strive to do better," he said to the Tsilhqot'in leaders.

Conservative MP Cathy McLeod, NDP MP Guy Caron and Green Leader Elizabeth May respond to the PM's apology 1:18

Landmark Supreme Court ruling

The full exoneration comes after a landmark 2014 Supreme Court of Canada ruling found that the Tsilhqot'in peoples had Aboriginal title to a large swath of their traditional territory — over 1,700 square kilometres — and not just to old village sites, as the provincial and federal governments had argued.

It was the first time in Canada that Aboriginal title had been confirmed outside of an Indian reserve.

Unlike the case in other areas of the country, few treaties were signed between Indigenous inhabitants and settlers in B.C.

Tl'etinqox Chief Joe Alphonse welcomed Trudeau's move to absolve Tsilhqot'in chiefs of any guilt related to the killings in 1864. (Jonathan Hayward/The Canadian Press)

First Nations leaders insist much of the province's territory is "stolen land," which has resulted in prolonged court battles to assert Aboriginal title rights and extinguish outstanding land claims.

The Tsilhqot'in style their tribal authority as the Tsilhqot'in National Government — a community with some 5,000 members — and insist it holds a status equal to both the federal and provincial governments.