Between 1931 and 1938 Sister Faustina Kowalska recorded in her Diary what she understood as Christ's request: that an image be painted as she saw him, with two rays, pale and red, from his heart; that the Sunday after Easter be kept as the Feast of Mercy; that the chaplet be prayed on rosary beads; and that the hour of his death, three in the afternoon, be remembered. The first image was painted in Vilnius in 1934.
The devotion spread across Poland and was briefly restricted by the Holy See in 1959 on the basis of faulty translations; the ban was lifted in 1978, six months before the archbishop of Kraków who had pressed for her cause became Pope. St. John Paul II canonized Faustina on April 30, 2000, and that day established Divine Mercy Sunday for the universal Church. He died on the vigil of the feast in 2005.
The Divine Mercy Sanctuary at Kraków-Łagiewniki is the devotion's home: the convent chapel with the image and Faustina's tomb, and the basilica consecrated by John Paul II in 2002. The Hour of Mercy is prayed there at 3 p.m. every day. The Sanctuary of St. John Paul II stands beside it.