pope from 1261 to 1264.

Of humble origin, he was first a priest at Lyon and then professor of canon law at Paris before being elevated to the bishopric of Verdun in 1253. Two years later he was made patriarch of Jerusalem by Pope Alexander IV, whom he succeeded on Aug. 29, 1261. Urban was faced with three tasks: freeing the Kingdom of Sicily, a papal fief, from Hohenstaufen domination; reasserting papal influence in Italy, where it had diminished because of Alexander's vacillation in the Sicilian problem; and restoring order in Rome, which suffered such civil unrest that Urban never resided there as pope.

In 1263 Urban fatefully decided to offer the crown of Sicily to Charles of Anjou (Charles I), the able and ambitious brother of King St. Louis IX of France, despite the claims of Manfred, illegitimate son of the late Hohenstaufen emperor Frederick II. By this time Urban had considered Manfred's power and the rise of the Ghibellines (anti-papal and pro-imperialistic political party) in Tuscany and Lombardy a critical threat to the church. Later negotiations between the Pope and Louis were tedious, menaced by both Manfred and the Ghibellines. Concurrent intrigue, including the suspicion of a plot to assassinate Urban, caused the Pope to leave for Perugia. He died, however, before Charles arrived, leaving the Sicilian problem to torment his successors.

Urban's bull of 1264 had ordered the whole church to observe the Feast of Corpus Christi, a festival in honour of the Real Presence of Christ in the Eucharist (observed on the Thursday after Trinity Sunday). Because of Urban's early death, the order was ignored in most countries until after its confirmation by Pope Clement V at the Council of Vienne in 1311–12. J. Guiraud's edition of Les Registres d'Urbain IV, 1261–64 (2 vol.) was published in 1901–30.