1911 Encyclopædia Britannica/John III. of Portugal
JOHN III. (1502-1557), king of Portugal, was born at Lisbon, on the 6th of June 1502, and ascended the throne as successor of his father Emmanuel I. in December 1521. In 1 524 he married Catherine, sister to the Emperor Charles V., who shortly afterwards married the infanta Isabella, John's sister. Succeeding to the crown at a time When Portugal was at the height of its political power, and Lisbon in a position of commercial importance previously unknown, John III., unfortunately for his dominions, became subservient to the clerical party among his subjects, with disastrous consequences to the commercial and social prosperity of his kingdom. He died of apoplexy on the 6th of June 1557, and was succeeded by his grandson Sebastian, then a child of only three years.