CUT KNIFE, Sask. - Prime Minister Justin Trudeau has exonerated a Saskatchewan chief of treason more than 130 years after the conviction.

The exoneration of Chief Poundmaker was announced at the reserve that bears his name -- Poundmaker Cree Nation -- about 200 kilometres northwest of Saskatoon.

Following prayers and traditional drumming, Trudeau told a crowd that the government must acknowledge wrongs of the past and that Poundmaker was unjustly convicted.

Poundmaker is considered an important political leader who spoke out against unfulfilled Treaty 6 promises and stood up for his people at the time of the 1885 Northwest Rebellion.

He was labelled a traitor even though he was known as a peacemaker and stopped First Nations fighters from going after retreating federal forces that had attacked them.

Poundmaker was tried for treason in Regina and imprisoned at Stony Mountain penitentiary in Manitoba before he was released because of poor health.

He died in 1886.