Ave verum corpus is a short Eucharistic chant that has been set to music by many composers. It dates to the 13th century, first recorded in a central Italian Franciscan manuscript (Chicago, Newberry Library, 24). A Reichenau manuscript of the 14th century attributes it to Pope Innocent (variously identified as Innocent III, Innocent IV, Innocent V, or Innocent VI[1])
During the Middle Ages, it was sung at the elevation of the Eucharist during the consecration at Mass. It was also used frequently during Benediction of the Blessed Sacrament.
The prayer is a meditation on Jesus's Real Presence in the Blessed Sacrament, and ties it to the redemptive meaning of suffering in the life of all believers.