Urban IV in the context of "Sicut Judaeis"

Manfred (Sicilian: Manfredi di Sicilia; 1232 – 26 February 1266) was the last King of Sicily from the Hohenstaufen dynasty, reigning from 1258 until his death. The natural son of the Holy Roman Emperor Frederick II, Manfred became regent over the Kingdom of Sicily on behalf of his nephew Conradin in 1254. As regent he subdued rebellions in the kingdom, until in 1258 he usurped Conradin's rule. After an initial attempt to appease Pope Innocent IV, he took up the ongoing conflict between the Hohenstaufens and the papacy through combat and political alliances. He defeated the papal army at Foggia on 2 December 1254. Excommunicated by three successive popes, Manfred was the target of a Crusade (1255–1266) called first by Pope Alexander IV and then by Urban IV. Nothing came of Alexander's call, but Urban enlisted the aid of Charles of Anjou in overthrowing Manfred. Manfred was killed during his defeat by Charles at the Battle of Benevento, and Charles assumed kingship of Sicily.

The Feast of Corpus Christi (Ecclesiastical Latin: Dies Sanctissimi Corporis et Sanguinis Domini Iesu Christi, lit. 'Day of the Most Holy Body and Blood of Jesus Christ the Lord'), also known as the Solemnity of the Most Holy Body and Blood of Christ, is a liturgical solemnity celebrating the real presence of Christ in the Eucharist; the feast is observed by the Catholic Church, in addition to certain Western Orthodox, Lutheran, and Anglican churches. Two months earlier, the institution of the Eucharist at the Last Supper is observed on Maundy Thursday in a sombre atmosphere leading to Good Friday. The liturgy on that day also commemorates Christ's washing of the disciples' feet, the institution of the priesthood, and the agony in the Garden of Gethsemane.

The feast of Corpus Christi was proposed by Thomas Aquinas, Doctor of the Church, to Pope Urban IV, in order to create a feast focused solely on the Holy Eucharist, emphasizing the joy of the Eucharist being the Body and Blood, Soul and Divinity of Jesus Christ. Having recognized in 1264 the authenticity of the Eucharistic Miracle of Bolsena, on input of Aquinas, the pontiff, then living in Orvieto, established the feast of Corpus Christi as a Solemnity and extended it to the whole Catholic Church.