Edward III was 14 when he was crowned King and assumed government in his own right in 1330. In 1337, Edward created the Duchy of Cornwall to provide the heir to the throne with an income independent of the sovereign or the state. An able soldier, and an inspiring leader, Edward founded the Order of the Garter in 1348.
At the beginning of the Hundred Years War in 1337, actual campaigning started when the King invaded France in 1339 and laid claim to the throne of France. Following a sea victory at Sluys in 1340, Edward overran Brittany in 1342 and in 1346 he landed in Normandy, defeating the French King, Philip VI, at the Battle of Crécy and his son Edward (the Black Prince) repeated his success at Poitiers (1356).
By 1360 Edward controlled over a quarter of France. His successes consolidated the support of the nobles, lessened criticism of the taxes, and improved relations with Parliament.
However, under the 1375 Treaty of Bruges the French King, Charles V, reversed most of the English conquests; Calais and a coastal strip near Bordeaux were Edward's only lasting gain.
Failure abroad provoked criticism at home. The Black Death plague outbreaks of 1348-9, 1361-2 and 1369 inflicted severe social dislocation (even the King lost a daughter to the plague) and caused deflation; severe laws were introduced to attempt to fix wages and prices.
In 1376, the 'Good Parliament' (which saw the election of the first Speaker to represent the Commons) attacked the high taxes and criticised the King's advisers. The ageing King withdrew to Richard II became King as Edward's eldest son, known as the 'the Black Prince' had died in 1376.