Edward III was the oldest
son of
King Edward II of
England and came to the
throne at the age of 14 when his
father was deposed by the armies of
his mother and her lover. Edward started
the Hundred Years War, originally over the Flemish
wool trade; he had a claim to the throne of
France because his mother had been the sister of King Charles IV. But the
Salic Law the French used said that the throne could not pass through a
woman, so the nearest heir descended through a male line became king. Edward accepted this for the first 10 years after Charles' death, but decided to press his claim on the advice of weavers in
Flanders with whom he'd made an important economic agreement in 1338.
Philip VI of France decided that Edward's claiming the French throne was an act of war and invaded the cities that were Edward's in France. Edward defended them, and won victories at Crecy and Poitiers. Edward's son Edward, the Black Prince became a hero in these wars. However, the war went on and on; English strength was greatly reduced by the outbreak of bubonic plague ("The Black Death") in 1349, and in 1360 a treaty was signed where Edward renounced his claim to France. But in 1369 he started claiming it again; in 1376, the Black Prince died of dysentery and only five fortified towns on the coast of France remained in English hands.
During Edward's reign, he did do some things in his own country; Parliament was divided into two houses, English rather than French became the language used in courts of law, and the office of Justice of the Peace was first created. Edward also founded the Order of the Garter.
Edward died of a stroke on 21 June 1377 and was succeeded on the throne by his 10-year-old grandson Richard II.