On May 13, 1917, the Virgin Mary appeared at the Cova da Iria in Fatima to the three shepherds Jacinta, Francisco and Lucia. It was an apparition that was repeated on the 13th of every month, for six consecutive months.
The Virgin asked them to pray the rosary for the conversion of sinners and revealed three messages.
In the first message she showed hell to them. In the second, the Virgin Mary said that Russia would be converted to Christianity which would bring peace.
The third message was the secret of Fatima, which was revealed by the pope in 2000. There they saw a bishop dressed in white that at the top of a mountain knelt at the foot of a cross where soldiers shot him. They also saw the death of bishops, priests, religious and laity. Many say that the vision led toward the persecution of Christians, throughout the twentieth century, causing an estimated 45 million victims because due to their faith. John Paul II was also the victim of an assassination attempt that took place in St. Peter's Square on May 13, 1981. He said he survived the shooting thanks to the intercession of the Virgin Mary. One year later, he even traveled to Fatima and placed in the crown the bullet that had struck him.
Today, Fatima is one of the most important pilgrimage sites in the world. The shepherd seers Francisco and Jacinta were declared blessed on May 13th in 2000. Lucia died in 2005 and a study on her life is under way that could lead to a possible beatification.