Surrounded as she was by priestly counsellors whom she respected, she nevertheless manifested plainly her impatience of the clerical usurpation of the rights of the Crown. The chief of these abuses was no doubt that practised by the Pontiff himself, in conferring upon foreigners the highest and richest benefices of the Church of Spain, ignoring that it was the prerogative of the Crown to name the bishops--always subject to papal confirmation. That Isabella, devout and priest-surrounded as she was, should have dared to oppose the Holy See and the terrible Pope Sixtus IV, as fearlessly as she had opposed her predatory nobles, is perhaps the highest proof that history can yield of her strength of character. Her smouldering indignation flared out when the Pope, ignoring her nomination of her chaplain, Alonzo de Burgos, to the vacant bishopric of Cuenca, appointed his own nephew, Raffaele Riario, Cardinal of San Sisto, to that vacant see. Twice already had she sought the pontiff’s confirmation of nominees of her own for other benefices--the Archbishopric of Saragoza and the Bishopric of Tarragona--and on each occasion her nominee had been set aside in favour of a creature of the Pope’s. But this third contemptuous disregard of her prerogative was more than her patience could endure. The Catholic Sovereigns refused to ratify the appointment of Riario, and begged the Pope--submissively at first--to cancel it. But the harsh, overbearing Sixtus returned an answer characteristic of his arrogant nature. It was his, he announced, to distribute at his pleasure all the benefices of Christendom; and he condescended to explain that the power which it had pleased God to confer upon him on earth could not be limited by any will but his own, and that it was governed only by the interests of the Catholic Faith, of which he was the sole arbiter. But his stubbornness met a stubbornness as great. The Catholic Sovereigns replied by withdrawing their ambassador from the Papal Court, and issuing an injunction to all Spanish subjects to leave Rome. Matters were becoming strained; an open rupture impended between Spain and the Vatican. But the Sovereigns had notified the Pope that it was their intention to summon a general council of the Church to settle the matter in dispute, and no Pope of those days could contemplate with equanimity a general council assembled for the purpose of sitting in judgment upon his decrees. Whatever the result, since at these councils the papal authority was questioned, it must follow that thereafter that authority would be impaired. Therefore this was the stock threat employed to bring a recalcitrant pontiff to a reasonable frame of mind.