John of Segovia, a Spanish theologian, b. at Segovia towards the end of the fourteenth century; d. probably in 1458. Nothing is known of him before he took part in the Council of Basle, except that he was archdeacon at Villaviciosa, canon at Toledo, and professor of theology at the University of Salamanca. In 1432 the University of Salamanca and King John II of Castile sent him as their representative to the Council of Basle, where he was one of the ablest defenders of the superiority of the council over the pope. At first he endeavored to mitigate the conflict between the council and Pope Eugene IV, with whom he spent some time at Florence in 1435, but afterwards he became one of the chief supporters of the revolutionary party at the council. He took part in the twenty-eighth session (October 1, 1437) at which Eugene IV was declared contumacious, and in the thirty-third session (May 16, 1439) at which the pope was declared a heretic. In March, 1439, John of Segovia represented the council at the Diet of Mainz. After Eugene IV was deposed by the council on June 25, 1439, John of Segovia was appointed one of the committee whose duty it was to select a number of theologians to elect the new pope. He was one of the thirty-three who on November 5, 1439, elected the antipope Felix V. In recognition for his services he was created cardinal by the anti-pope on October 12, 1440. He represented Felix V at the Parliament of Bourges in 1440, at the Diet of Mainz in 1441, and that of Frankfort in 1442. At the end of the schism in 1449 he resigned the cardinalate, was appointed titular Bishop of Caesarea by Eugene IV, and retired to a Spanish monastery. His most important literary work is an extensive history of the Council of Basle, “Historia generalis concilii Basiliensis. Libri XVIII”, edited by Birk and Beer in “Monumenta conciliorum generalium saeculi decimi quinti: Scriptor.”, II-IV (Vienna, 1873-96). His other works are a treatise in favor of the Immaculate Conception of our Lady, printed at Brussels in 1664; a refutation of the Koran, entitled “De mittendo gladio in Saracenos”; a defense of the “Filioque” against the Greeks, entitled “De processu Spiritus Sancti” (Basle, 1476); a Biblical concordance, “Concordantiae biblicae vocum indeclinabilium” (Basle, 1476); and a few works defending the superiority of a general council over the pope.