The term refers to a succession of wars between England and France. The fighting began in 1337 and did not end until 1453. However, the period was not one of constant warfare: truces and treaties brought about breaks in the military action between the countries. The reasons for the conflicts were many: England was trying to hang onto its provinces on the European continent; the French threw their support behind the Scots, who had their own battles with the English; the French wished to control the commercial center of Flanders (present-day Belgium), where the English had set up a profitable wool trade; and finally, the two countries disagreed about who should control the English Channel, the body of water that lies between them.

To further complicate matters, marriages between the English and French aristocracy meant that heirs to either throne could find themselves with a foreign relative, allowing them to lay claim to authority over the other country as well. When the first war broke out in 1337, King Edward III (1312–1377) of England claimed the French throne on the basis of the fact that his mother, Isabella, was the daughter of France’s King Philip IV (called Philip the Fair; 1268–1314) and the sister of three French kings. Over the course of the next century, even though England won most of the battles and for a brief time controlled France (1420–22), it was the French who ultimately won the war in 1453. England lost all its territory on the continent, except Calais, which was also later taken by the French (in 1558).