In 2008, the Government of Canada established a truth commission to find out what went on between the years 1831 and 1996 when an estimated 150,000 Aboriginal children were subjected to various forms of abuse in specially established boarding schools.
And a lot has emerged.
The system was based on the children being forcibly separated from their families to be indoctrinated in Western values through religious schools.
Both physical and sexual abuse occurred.
combined with consistent denial of the children's own cultures and languages.
Over the years, the indigenous people have received an apology from several other churches involved, but there has been silence from the Catholic Church.
But last year, the remains of 215 children were found at one of the boarding schools, putting more pressure on the Pope.
"A journey of penance"
He will now visit several cities and meet survivors of the schools in Canada that were run with the help of the Catholic Church.
The hope is that the trip will contribute to healing and reconciliation.
- We must all be aware that this is a journey of penance, Francis told reporters aboard the papal plane during the ten-hour journey from Rome to Edmonton.
During the stay, he will, among other things, visit Maskwacis, about 10 kilometers south of Edmonton, to speak before an audience of about 15,000 people.
Several in the audience will be former students at the boarding schools.
However, many believe that the apology is late.
- When I went to school, I lost a lot of my culture, my ancestry.
That's a lot of years of loss, said a former student.