Relics of the True Cross on which Christ was crucified were quickly and widely distributed after its legendary discovery in the fourth century by Saint Helena, mother of Constantine, the first Christian Roman emperor. Throughout the medieval period, such relics were housed in precious containers where they could be venerated by the faithful. This finely made small box decorated with cloisonné enamel and niello is one of the earliest examples of such a reliquary. The sliding lid, decorated with a Crucifixion scene and busts of saints, has four episodes from the life of Christ on its underside—the Annunciation, Nativity, Crucifixion, and Anastasis (or Descent into Limbo). The lid slides back to reveal five interior relic compartments arranged in the shape of a cross. On the lid, Christ, flanked by the mourning figures of the Virgin and Saint John, is shown alive on the cross, wearing a long tunic popular in Eastern depictions of this scene. Pope Innocent IV (r. 1243–54) is said to have owned this reliquary.