Francesco Piccolomini (Pius III) elected Pope

Pope Pius III (May 29, 1439 – October 18, 1503), born Francesco Todeschini Piccolomini, was Pope from September 22 to October 18, 1503.

He was born in Siena, the nephew of Aeneas Silvius Piccolomini, the future Pope Pius II, by his sister Laodamia. He was received as a boy into the household of Aeneas Silvius, who permitted him to assume the name and arms of the Piccolomini family (his brother Antonio being made Duke of Amalfi during the pontificate of Pius II). Pius II appointed him in 1460, when only 22 years of age, to the see of Siena, which he had just raised to an archbishopric and made him a cardinal, at his first consistory, 5 March 1460. Within months he sent him as legate to the March of Ancona, with the experienced bishop of Marsico as his counsellor. He proved studious and effective.
Cardinal Piccolomini participated in the conclave that elected Pope Paul II (1464–71) in 1464 but was absent when Pope Sixtus IV (1471–84) was elected in 1471. He was employed in several important legations, as by Paul II at the Imperial diet at Regensburg/Ratisbon, and by Sixtus IV to secure the restoration of ecclesiastical authority in Umbria. He participated in the conclave of 1484 which elected Innocent VIII and in the conclave of 1492 which elected Alexander VI. The cardinal was involved in Alexander's brief-lived effort to reform the Roman curia, following the murder of his son Giovanni Borgia (1474) in 1497.
In 1502 the Cardinal commissioned a library with access from an aisle of the Duomo di Siena, which was intended to house the library of humanist texts assembled by his uncle, and commissioned the artist Pinturicchio to fresco its vault and ten narrative panels along the walls depicting scenes from the life of Aeneas Silvius Piccolomini. Though Pinturrichio labored for five years, the books never reached their splendid destination; yet the Piccolomini Library is a monument of the High Renaissance in Siena. Some of Pope Pius III most famous portraits can be viewed in the Louvre museum. It gives an edited version of Pius' life, passing over his former support of the antipope Felix V.

Election to papacy
Main article: Papal conclave, September 1503
Amid the disturbances consequent upon the death of the Borgia Pope Alexander VI (1492–1503), it took the combined pressures of all the ambassadors to induce Cesare Borgia to withdraw from Rome, so that an unpressured conclave might take place. In it, Cardinal Piccolomini was elected Pope Pius III on September 22, 1503. This selection can be seen as a compromise between factions, Borgia and della Rovere, picking a frail cardinal with long experience in the Curia over the kin of either Sixtus IV or Alexander VI.
His coronation took place on October 8, 1503. He at once took in hand the reform of the papal court and arrested Cesare Borgia; but after a brief pontificate of twenty-six days he died (October 18, 1503) of an ulcer in the leg, or, as some have alleged, of poison administered at the instigation of Pandolfo Petrucci, governor of Siena.

B. at Siena, 29 May, 1439; elected 22 Sept., 1503; d. in Rome, 18 Oct., 1503, after a pontificate of four weeks. Piccolomini was the son of a sister of Pius II. He had passed his boyhood in destitute circumstances when his uncle took him into his household, bestowed upon him his family name and arms, and superintended his training and education. He studied law in Perugia and immediately after receiving the doctorate as canonist was appointed by his uncle Archbishop of Siena, and on 5 March, 1460, cardinal-deacon with the title of S. Eustachio. The following month he was sent as legate to the March of Ancona, with the experienced Bishop of Marsico as his counsellor. "The only thing objectionable about him", says Voigt (Enea Silvio, III, 531), "was his youth; for in the administration of his legation and in his later conduct at the curia he proved to be a man of spotless character and many-sided capacity." He was sent by Paul II as legate to Germany, where he acquitted himself with eminent success, the knowledge of German that he had acquired in his uncle's house being of great advantage to him. During the worldly reigns of Sixtus IV and Alexander VI he kept away from Rome as much as possible. Sigismondo de Conti, who knew him well tells us that "he left no moment unoccupied; his time for study was before daybreak; he spent his mornings in prayer and his midday hours in giving audiences, to which the humblest had easy access. He was so temperate in food and drink that he only allowed himself an evening meal every other day." Yet this is the excellent man to whom Gregorovius in his "Lucrezia Borgia", without a shadow of authority, gives a dozen children—the calumny being repeated by Brosch and Creighton. After the death of Alexander VI, the conclave could not unite on the principal candidates, d'Amboise, Rovere, and Sforza; hence the great majority cast their votes for Piccolomini, who though only sixty-four was, like his uncle, tortured with gout and was prematurely old. He took the name of Pius III in honour of his uncle, was crowned on 8 Oct., after receiving priestly and episcopal orders. The strain of the long ceremony was so great that the pope sank under it. He was buried in St. Peter's, but his remains were later transferred to S. Andrea della Valle where he rests by the side of Pius II.

Pius III, given name Francesco Nanni Todeschini Piccolomini, Roman Catholic Pope from the 22nd of September to the 18th of October 1503, was born at Siena on the 9th of May 1439. After studying law at Perugia, he was made Archbishop of Siena and cardinal-deacon of St. Eustachio, when only twenty-two years of age, by his uncle Pope Pius II, who permitted him to assume the name and arms of the Piccolomini. He was employed by subsequent popes in several important legations, as by Paul II at the diet of Regensburg, and by Pope Sixtus IV to secure the restoration of ecclesiastical authority in Umbria. He bravely opposed the policy of Pope Alexander VI, and was elected pope, amid the disturbances consequent upon the death of the latter, through the interested influence of Cardinal della Rovere, afterwards Pope Julius II, and was crowned on the 8th of October 1503. He permitted Cesare Borgia to return to Rome, but promptly took in hand the reform of the curia. Pius was a man of blameless life, and would doubtless have accomplished much had he lived. His successor was Julius II.