On 13 May 1981, John Paul II was shot four times in St Peter's Square by Mehmet Ali Agca, a Turkish gunman with ties to organized crime and possible, though never fully proven, links to Bulgarian and Soviet intelligence services eager to remove a pope seen as a threat to communist stability in Eastern Europe. He survived only after emergency surgery and a lengthy recovery, and later attributed his survival to the intercession of Our Lady of Fatima, since the shooting occurred on the anniversary of the first reported Fatima apparition of 1917.
In 1983 John Paul II visited Agca in his Roman prison cell and forgave him in person, a meeting photographed and widely circulated that became one of the defining images of his pontificate, presenting personal reconciliation as a public act rather than a private matter between the two men alone. The pope later had one of the bullets removed from his body set into the crown of the statue of Our Lady of Fatima in Portugal, a direct physical link between the attack and the devotion he credited with his survival.
The theme of mercy became a recurring emphasis of his later pontificate. Drawing on the private revelations of the Polish nun Faustina Kowalska, whom he beatified in 1993 and canonized in 2000, John Paul II instituted Divine Mercy Sunday as a feast for the universal church in the same year, fixed on the Sunday after Easter, formally establishing a devotion that had circulated in Poland for decades as part of the church's official calendar.