But the right of the Calatravans was never exercised, and the next grand master of the Knights of Aviz, Fernando Rodrigues de Sequeira, continued to assert supreme authority over them. The mission of the military orders in Portugal seemed to end after the overthrow of Muslim domination, but the Portuguese expeditions across the sea opened up a new field for them. The conquest of Ceuta by King João I (1415), the attacks upon Tangier under João's son Duarte (1437) were also crusades, inspired by a religious spirit and sanctioned by similar Papal Bulls. The Knights of Aviz and the Knights of Christ from Order of Christ, scions of the Knights Templars, achieved deeds of valour, the former under the Prince Fernando, the latter under Henrique, brother of King Duarte. Fernando displayed a no less heroic forbearance during his six years of captivity among the Muslims, a long martyrdom which after his death placed him among the Blessed (Acta SS.,5 June). This enthusiasm did not last, and the Crusade in Africa continued as a mercantile enterprise. After the grand mastership of the order had been vested in the King in perpetuity (1551), he availed himself of its income to reward any kind of service in the army or the fleet. If the wealth of the Knights of Aviz was not as great as that of the Knights of Christ, it was still quite large, drawn as it was from some forty-three commanderies. The religious spirit of the knights vanished, and they withdrew from their clerical brothers who continued alone the conventual life. They were dispensed from their vow of celibacy by Alexander VI (1502), who tolerated their marriage to prevent scandalous concubinage; Julius III (1551) allowed them to dispose freely of their personal properties. Nobility of birth remained the chief requirement of aspirants to the mantle, a requirement confirmed by a decree of 1604. Secularization of the order Pope Pius VI (1789) and Queen Mary I reformed the order into a secular institution. In 1834, when the civil government of Portugal abolished religious orders and monasteries, after the defeat of King Miguel in the Civil War, under the constitutional monarchy the order lost its properties. The ancient military orders were transformed by the liberal constitution and subsequent legislation into mere orders of merit. The privileges which once had been an essential part of the membership of the old military orders also