Canadian Prime Minister Justin Trudeau, who has been criticized by some indigenous communities, on Thursday apologized and posthumously exonerated a Cree chief unjustly imprisoned for treason more than 130 years ago.

The Liberal prime minister received widespread support from Canada's First Nations when he ran for office four years ago promising to reconcile Canada with the native peoples wronged during the country's colonial past.

Chief Poundmaker, or Pihtokahanapiwiyin, was a Cree leader during Canada's North-West Rebellion of 1885. Historians have said he helped prevent a massacre of federal soldiers during a battle with the primarily French-speaking rebels, who were descendants of First Nation and European settlers.