Pius III, born Francesco Todeschini Piccolomini (May 9, 1439 - October 18, 1503), was pope from September 22 to October 18, 1503.

He was born in Siena, the nephew of Pius II by his sister Laodamia. He was received as a boy into the household of Pius II, who permitted him to assume the name and arms of the Piccolomini family (his brother Antonio being made Duke of Amalfi), and appointed him in 1460, when only twenty-two years of age, to the see of Siena, which he had just raised to an archbishopric and made him a cardinalate. 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.

In 1502 the cardinal commissioned a library with access from an aisle of the cathedral, 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, in the event, the books never reached their splendid destination; yet the library is a monument of the Early Renaissance in Siena.

Cardinal Piccolomini participated in the conclave that elected Paul II in 1464 but was absent when Sixtus IV 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.

Amid the disturbances consequent upon the death of the Borgia Alexander VI, 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, by the not wholly disinterested influence of Cardinal Rovere, elected pope on September 22, 1503, his installation taking place on the October 8 following. 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.

See Pope John Paul I for another example of a short pontificate generating conspiracy theories.

External links

• Catholic Encyclopedia: Pope Pius III
• Frida De Salve, "The Piccolomini Library"