Born Pietro dell Murrone, he was elected Pope July 5, 1294. His predecessor as Pope, Nicholas IV, died in April of 1292, and the Church went without a Pope for 27 months, as the 12 Cardinal electors couldn't agree on, well, pretty much anything. In October of 1293, following a few attempts at electing a Pope (broken up by summer vacations), another conclave was called in Perugia. This was doomed from the start. Charles II, King of Sicily, attempted to give the Cardinals a short list of four Cardinals for whom they should vote (the Cardinali declined his offer). By May and June, trouble broke out in Rome, fighting in Orvieto, and the death of a younger brother of one of the electors, Cardinal Napoleone.
Finally, they tried again in July. On July 5, 1294, Cardinal Latino Malabranca told his fellow conclavists that he had received a letter from a hermit telling him he had seen visions of great trouble ahead, if the Cardinals allowed the Church to go any longer without a pope. When asked the identity of the hermit, Cardinal Malabranca indicated it came from Pietro del Murrone, a Priest and founder of a community of Benedictines who later returned to the hermetical life. He was well known among the clergy of the region, as well as the Cardinal electors. Starting with Malabranca, the Cardinals eventually cast their votes for del Murrone. He was 85 years old at the time of his election.
Why did the Cardinals vote for him? Many reasons: perhaps tired of the stalemate or a desire for a change from the past. Though he protested his election as Pope, he eventually accepted. On August 29, he was carried by a donkey and escorted by Charles II to the church of Santa Maria del Colmaggio, where he was consecrated Bishop and took the name Celestine V.
History tells us he wasn't the best of Popes, though not because he was corrupt. Advanced age, combined with the pushy King Charles, made his pontificate a bit of a mess. The King insisted that the Pope take up residence not in Rome, but in Naples. Here the King was able to get his clergy friends named to key curial positions, as well as get himself named the "guardian" for the next conclave.
Pope Celestine knew he was ill prepared for the papacy, and actually resigned from the Petrine office on December 13, 1294. Now back to being "Fra Pietro", he had hoped to return to hermetical life. But his successor, Pope Boniface VIII, feared that the ex-pope could be used in an attempt to unseat him. The Pope confined him to a house arrest, and though he managed to escape for a time, he was eventually confined to a tower in Castel Fumone. There, though not mistreated, he died of an infection from an absess on May 19, 1296. His remains were transferred to Sta. Maria di Colemaggio in 1317.