From the longer Wikipedia page 
Pope Pius II (Latin: Pius PP. II, Italian: Pio II), born Enea Silvio Bartolomeo Piccolomini (Latin Aeneas Silvius Bartholomeus; 18 October 1405 – 14 August 1464) was the head of the Catholic Church from 19 August 1458 to his death in 1464. He was born at Corsignano in the Sienese territory of a noble but decayed family. His longest and most enduring work is the story of his life, the Commentaries, which is the only autobiography ever written by a reigning Pope. He is also known for his erotic writings done before he became pope.
After allying himself with Ferdinand II of Aragon, the Aragonese claimant to the throne of Naples, his next important act was to convene a congress of the representatives of Christian princes at Mantua for joint action against the Turks. On 26 September 1459 he called for a new crusade against the Ottomans and on 14 January 1460 he proclaimed the official crusade that was to last for three years. His long progress to the place of assembly resembled a triumphal procession, and the Council of Mantua of 1459, a complete failure as regards its ostensible object of mounting a crusade, at least showed that the impotence of Christendom was not owing to the Pope. The Pope did, however, influence Vlad III Dracula — whom the Pope held in high regard — in starting a war against Sultan Mehmed II of Turkey. This conflict at its peak involved the Wallachians trying to assassinate the Sultan (see The Night Attack).
On his return from the congress, Pius II spent a considerable time in his native district of Siena, where he was joined by his erstwhile host in Mantua Ludovico III Gonzaga, Marquis of Mantua. Pius described his delight with country life in very pleasing language. He was recalled to Rome by the disturbances occasioned by Tiburzio di Maso, who was ultimately seized and executed. In the struggle for the Kingdom of Naples between the supporters of the House of Aragon and the House of Anjou, the Papal States were at this time troubled by rebellious barons and marauding condottieri, whom he gradually, though momentarily, quelled. The Neapolitan War was also concluded by the success of the Pope's ally the Aragonese Ferdinand. In particular, the Pope engaged for most of his reign in what looked like a personal war against Sigismondo Pandolfo Malatesta, Lord of Rimini, with the result of the almost complete submission of that condottiero. Pius II also tried mediation in the Thirteen Years' War of 1454–66 between Poland and the Teutonic Knights, but, when he failed to achieve success, cast an anathema over Polish and Prussians both. Pius II was also engaged in a series of disputes with the Bohemian King George of Poděbrady and the Sigismund of Austria (who was excommunicated for having arrested Nicholas of Cusa, Bishop of Brixen).
In July 1461, Pius II canonized Saint Catherine of Siena, and in October of the same year he gained at first what appeared to be a brilliant success by inducing the new King of France, Louis XI, to abolish the Pragmatic Sanction of Bourges (Wikipedia page ), by which the Pope's authority in France had been grievously impaired. But Louis XI had expected that Pius II would in return espouse the French cause in Naples, and when he found himself disappointed he virtually re-established the Pragmatic Sanction by royal ordinances. In September 1462, he confirmed the Diocese of Laibach, established in December 1462 by Frederick III, Holy Roman Emperor.
The crusade for which the Congress of Mantua had been convoked made no progress. The Pope did his best: he addressed an eloquent letter to the Sultan of Turkey urging him to become a Christian, a letter that probably never was sent. Not surprisingly, if it was delivered, this invitation was not successful. A public ceremony was staged to receive the relics of the head of Saint Andrew when it was brought from the East to Rome. Pius II succeeded in reconciling the Emperor and the King of Hungary, and derived great encouragement as well as pecuniary advantage from the discovery of mines of alum in the papal territory at Tolfa. But France was estranged; the Duke of Burgundy broke his positive promises; Milan was engrossed with the attempt to seize Genoa; Florence cynically advised the Pope to let the Turks and the Venetians wear each other out. Pius II was unaware he was nearing his end, and his malady probably prompted the feverish impatience with which on 18 June 1464 he assumed the cross and departed for Ancona to conduct the crusade in person.
Pius condemned slavery of newly baptised Christians as a "great crime" in an address of 1462 to the local ruler of the Canary Islands.Pius instructed bishops to impose penalties on transgressors. Pius did not condemn the concept of trading in slaves, only the enslavement of the recently baptised, who represented a very small minority of those captured and taken to Portugal. Pope Urban VIII, in his bull dated 22 April 1639, described these grave warnings of Pius (7 October 1462, Apud Raynaldum in Annalibus Ecclesiasticis ad ann n.42) as relating to "neophytes". According to British diplomatic papers, Pius' letter was addressed to Bishop Rubeira and confirms Urban's observation that the condemnation relates to new converts being enslaved.
In spite of suffering from a fever, Pope Pius II left Rome for Ancona in the hope of increasing the morale of the crusading army. However, the crusading army melted away at Ancona for want of transport, and when at last the Venetian fleet arrived, the dying Pope could only view it from a window. He expired two days afterwards, on 14 August 1464, and was succeeded by Pope Paul II. Pius II's body was buried in the church of Sant'Andrea della Valle, while an empty cenotaph was built in St. Peter's Basilica. Later, the cenotaph was moved to Sant'Andrea as well.