It took Ghiberti 21 years to complete the doors. These gilded bronze doors consist of twenty-eight panels, with twenty panels depicting the life of Christ from the New Testament, and on April 19, 1424 they were placed on the side of the Baptistery. Twenty panels showing the life of Christ from the New Testament are depicted: the "Annunciation, Nativity, Adoration of the Magi, Dispute with the Doctors, Baptism of Christ, Temptation of Christ, Chasing the Merchants Away, Christ Walking on Water, Transfiguration, Resurrection of Lazarus," "Christ’s Arrival in Jerusalem, Last Supper, Agony in the Garden, Christ Being Captured, Flagellation, Christ on Trial with Pilate, Trip to Calvary, Crucifixion, Resurrection, and Pentecost." The eight lower panels show the four evangelists and the Church Fathers: Saint Ambrose, Saint Jerome, Saint Gregory and Saint Augustine. The panels are surrounded by a framework of foliage in the door case and gilded busts of prophets and sibyls at the intersections of the panels. Originally installed on the east side in place of Pisano's doors, they were later moved to the north side. They are described by the art historian Antonio Paolucci as "the most important event in the history of Florentine art in the first quarter of the 15th century".