Pope Francis visited Turin, Italy, on Monday where he asked forgiveness for the persecution the Catholic Church brought upon the Waldensians during the Middle Ages.

“On the part of the Catholic Church, I ask your forgiveness, I ask it for the non-Christian and even inhuman attitudes and behavior that we have showed you,” Pope Francis said.

He added: “In the name of the Lord Jesus Christ, forgive us!”

The Waldensian church was founded in the 12th century by Peter Waldo, a wealthy merchant from Lyon, France. The Waldensians recognized that they were the true successors of the apostolic Church. They obeyed the laws of both the Old and New Testaments, including weekly Saturday Sabbath observance and the Bible-ordained holy days.

Catholic Church officials condemned these practices because they contradicted the Vatican’s doctrines.

In 1184, Pope Lucius labeled the Waldensians as heretics. Within a few years, the persecution intensified, with a command issued that all Waldensians in certain areas be burned at the stake. Many Waldensians fled to the area near Turin.

In 1208, Pope Innocent iii declared the Albigensian Crusade—an attack not only against the Waldensians, but also against the civil rulers who protected them. Many Waldensians were killed and displaced.

At present, there are some 45,000 people around the world who claim to be “Waldensian”—mostly in Italy, Argentina and Uruguay. But it is important to note that these modern groups do not adhere to the doctrines that differentiated the Waldensians of the Middle Ages from Catholics. The teachings of modern “Waldensians” are in line with those of mainstream Protestants.

Pope Francis’s plea for forgiveness marks a rare acknowledgement by the Vatican of one of the Catholic Church’s dark chapters.

To understand the astonishing historic significance of the Waldensians, and to learn why the Catholic Crusaders were unable to stamp them out, read The True History of God’s True Church.