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 what at first appeared to be a brilliant success by inducing the new king of France, Louis XI, to abolish the Pragmatic Sanction of Bourges, by which the papal 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. Pius II built a fortress in Tivoli called Rocca Pia in 1461. In September 1462, he confirmed the Diocese of Ljubljana, established in December 1462 by Frederick III, Holy Roman Emperor. The crusade for which the Congress of Mantua had been convoked made no progress. In November 1463, Pope Pius II tried to organize the crusade against the Ottomans, similar to what Nicholas V and Calixtus III had tried to do before him. Pius II invited all the Christian nobility to join, and the Venetians immediately answered the appeal. So did George Kastriot Skanderbeg the leader of Albanian resistance, who on 27 November 1463 declared war on the Ottomans and attacked their forces near Ohrid. Pius II's planned crusade envisioned assembling 20,000 soldiers in Taranto, and another 20,000 would be gathered by Skanderbeg. They would have been marshaled in Durazzo under Skanderbeg's leadership and would have formed the central front against the Ottomans. The Pope did his best: he addressed an eloquent letter to the Ottoman ruler, Mehmet II, urging him to become a Christian, a letter that probably never was sent. However, there are historians who believe that the mentioned letter was sent to the Sublime Porte. Not surprisingly, if it was delivered, the 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. However, 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