Despite his relatively short reign, Henry's military successes in the Hundred Years' War against France made England one of the strongest military powers in Europe. During the reign of his father Henry IV, he gained military experience fighting the Welsh during the revolt of Owain Glyndŵr and against the powerful Percy family of Northumberland at the Battle of Shrewsbury. Henry acquired an increasing role in England's government due to the king's declining health. After his father's death in 1413, Henry assumed control of the country and asserted the pending English claim to the French throne. In 1415, Henry embarked on war with France in the ongoing Hundred Years' War (1337–1453) between the two nations. His military successes culminated in his famous victory at the Battle of Agincourt (1415) and saw him come close to conquering France. Taking advantage of political divisions within France, he conquered large portions of the kingdom, resulting in Normandy's occupation by the English for the first time since 1345–1360. After months of negotiation with Charles VI of France, the Treaty of Troyes (1420) recognised Henry V as regent and heir apparent to the French throne, and he was subsequently married to Charles's daughter, Catherine of Valois. Everything seemed to point to the formation of a union between the kingdoms, in the person of Henry. However, he died two years later and was succeeded by his only child, the infant Henry VI. (Wikipedia)