Pope Urban VI - Wikipedia

Urban VI, born Bartolommeo Prignani (1318 - 1389), pope (1378 to 1389), was a native of Naples. A devout monk and learned casuist, he became archbishop of Bari in 1377, and, on the death of Gregory XI, the Roman populace clamorously demanding an Italian pope, was unanimously chosen (April 8, 1378) by the French cardinals. The arrogant and imperious temper of the new pope, intoxicated by his unexpected fortune, showed itself in ways so intolerable that five months afterwards the majority of the cardinals met at Fondi, and, repudiating their previous action, proceeded to elect Robert of Geneva (September 20), who assumed the title of Clement VII[?]. Thus began the Great Schism which divided Christendom for nearly forty years.

The measures of Urban were not without vigour, but at the same time were characterized by such a want of prudence and self-control as has given rise to the not improbable assertion that he actually was, at times at least, a lunatic. Clement VII was of course, excommunicated, and designated the Antichrist; twenty-six new cardinals were created in a single day, and by an arbitrary alienation of the estates and property of the church, funds were raised for open war.

The castle of St Angelo was besieged and taken, and the antipope Clement VII put to flight, while Charles of Durazzo[?] was invested in the sovereignty of Naples, forfeited by Queen Joanna. Later, Charles began to resist the papal pretensions, and Urban was shut up in Nocera, from the walls of which he daily fulminated his anathemas against his besiegers; he afterwards succeeded in making his escape to Genoa, and on the death of Charles, set himself at the head of his troops, apparently with the intention of seizing Naples for his nephew if not for himself. To raise funds he proclaimed a Jubilee, though only thirty-three years had elapsed since that celebrated under Clement VI, but before the celebration he died at Rome of injuries caused by a fall from his mule, on October 15, 1389. His successor was Boniface IX.

from the 9th edition (1888) of an unnamed encyclopedia.