and Romanus Pontifex which recognized Portugal's trade rights in territories it had discovered along the West African coast. This confirmation of Romanus Pontifex also gave the Portuguese the military Order of Christ under Henry the Navigator. Callixtus III ordered a new trial for Joan of Arc (c. 1412–1431), at which she was posthumously vindicated. Callixtus III canonized the following four saints during his pontificate: Vincent Ferrer (3 June 1455), Osmund (1 January 1457), Albert of Trapani (15 October 1457), and Rose of Viterbo (1457). Callixtus III elevated nine new cardinals into the cardinalate in two consistories on 20 February 1456 and 17 December 1456, two of whom were cardinal nephews. The first of them was Rodrigo de Borgia who later became Pope Alexander VI (1492–1503), infamous for his corruption and immorality. The second was Luis Julian de Milà. The pope approved of the establishment of the University of Greifswald in 1456. According to one story that first appeared in a 1475 posthumous biography and was subsequently embellished and popularized by Pierre-Simon Laplace, Callixtus III excommunicated the 1456 appearance of Halley's Comet, believing it to be an ill omen for the Christian defenders of Belgrade from the besieging armies of the Ottoman Empire. No known primary source supports the authenticity of this account. The 29 June 1456 papal bull of Callixtus III calling for a public prayer for the success of the crusade makes no mention of the comet. By 6 August, when the Turkish siege was broken, the comet had not been visible in either Europe or Turkey for several weeks. Death Callixtus III died on 6 August 1458. His remains were transferred in 1586 and again in 1610 with the remains of his nephew Alexander VI to Santa Maria in Monserrato. His remains were transferred once more on 21 August 1889 in the chapel of San Diego. In his will he left 5000 ducats to establish a hospital. Legacy Catholic historian Ludwig von Pastor opined: See also List of popes from the Borgia family Cardinals created by Callixtus III Route of the Borgias References Citations Bibliography Davenport, Frances Gardiner, editor (1917). European treaties bearing on the history of the United States and its Dependencies to 1648, Carnegie Institute of Washington. Gower, Ronald Sutherland (2007). Joan of Arc, BiblioBazaar LLC. Montor, Artaud de; François, Alexis (1911). The Lives and Times of the Popes, Vol. 4. Catholic Publication Society of America.