The English king Henry V, b. Sept. 16?, 1387, was a brilliant military
organizer who conquered France. After succeeding his father, Henry IV, in
1413, he quelled minor revolts by the Lollard heretic Sir John Oldcastle
(1414) and by nobles supporting the claim of the Mortimer family to the crown
(1415). He then united the country in a revival of the Hundred Years' War
against France.
On his first campaign, in 1415, Henry inflicted a crushing defeat on the
divided French nobility in the Battle of Agincourt. In 1417 he started an
ambitious war of conquest that led to the occupation (1419) of Normandy. By
the Treaty of Troyes (1420), Henry was recognized as heir of Charles VI of
France and married Charles's daughter Catherine. With only the resistance of
the dauphin (the future Charles VII) impeding the complete conquest of France,
Henry died on Aug. 31, 1422. He was succeeded by his 9-month-old son, Henry
VI.