Dom Pedro, duke of Coimbra and regent of Portugal, born in Lisbon, Dec. 9, 1392, killed in battle, May 20, 1449. He was the second son of John I. of Portugal and Philippa of Lancaster, daughter of John of Gaunt. While yet young he was intrusted with the command of the first expedition against Ceuta. He next devoted four years (1424-'8) to travel, visiting all the courts of Europe, and penetrating even to Bagdad. After the death of King Edward (Don Duarte) the people became discontented with the regency of the queen, and Dom Pedro was nominated by. the cortes defender and regent of the kingdom, Nov. 11,1439. He brought about a marriage between his daughter Isabella and the young king, Alfonso V. (1446). A quarrel between himself and his illegitimate brother the duke of Braganca, each claiming the dignity of constable of the kingdom, resulted in civil war. Braganca gained the king to his interest. Pedro having retired to Coimbra, but not daring to sustain a siege, advanced to meet the royal troops with a force of 1,000 horse and 5,000 infantry; and in the battle of Alfarrobeira, May 20, 1449, he was defeated, and killed by an arrow.