Between 1916 and 1917, three shepherd children — Lúcia, Francisco, and Jacinta — reported apparitions of the Angel of Peace and of a lady who identified herself as the "Lady of the Rosary." She entrusted them with three secrets: a vision of Hell along with a call to devotion to the Immaculate Heart of Mary; a prediction of the end of World War I, the beginning of World War II, and a request for the consecration of Russia; and a vision of a "bishop dressed in white," interpreted as the assassination attempt on Pope John Paul II in 1981. The bullet that struck him was later placed in the crown of the statue of Our Lady of Fátima, as a symbol of gratitude and faith in divine protection.

Beyond the messages, Fátima became known for reports of miracles and healings, such as the restoration of sight, recovery from paralysis, and other serious illnesses. These testimonies, combined with the spiritual impact of the apparitions, turned Fátima into one of the most important pilgrimage destinations in the world.