NICCOLÒ IV, POPE. — Girolamo, born into a humble family at Lisciano near Ascoli Piceno, entered the Friars Minor at a very young age and held various offices among them. Appointed provincial of Dalmatia by s. Bonaventura in 1272, he was immediately commissioned by Gregory X, together with three companions, to conduct negotiations for the reunion of the Church of the East with Michele VIII Paleologo, emperor of Constantinople.
In the meantime, s. Bonaventura having died, Friar Girolamo was elected to succeed him as minister general (20 May 1274), and at Lyons on 24 June, during the Council, he reported on the union that had taken place with the East. Employed on peace missions, he was created cardinal of S. Pudenziana by Niccolò III (12 March 1278); upon the death of Onorio IV, after a ten-month interregnum during which Friar Girolamo courageously worked to bring about the election of his successor, he himself was elected on 22 Feb. 1288, taking the name of N. IV. He worked with great fervor for the missions among the Mongols in Persia and among the Chinese and Tartars, and for the reunion of the Catholic Church with the dissidents of the East. He also attempted, with armed forces of his own, to stem the invasion of the Mamluks of Egypt against what remained of the Kingdom of Jerusalem, but he could not prevent the fall of S. Giovanni d'Acri, the last bulwark of Christendom (1291). Appointed by the Romans as their senator, he took care to restore peace in Rome, relying especially for this purpose on Giovanni Colonna. At Rieti he crowned Carlo II d'Angiò (29 May 1289), issuing him the diploma of investiture, while taking great care not to favor the factionalism of the Guelphs. At Orvieto he laid the first stone of the Duomo; in Rome he built a palace at S. Maria Maggiore and stayed there; through his efforts that Basilica was adorned with mosaics, while those of the Lateran were restored. D. in Rome on 14 Apr. 1292; Sisto V later erected a monument to him at S. Maria Maggiore.