The "Hundred Years' War" between England and France had broken out for the first time in 1337, but had met a lull in 1347 after the English forces had succeeded in taking Calais. This largely resulted from the arrival in Europe of the Black Death in 1350. This devastating pandemic, now agreed to have been a manifestation of bubonic plague, killed between 30 and 60 per cent of Europe's population. In 1355, however, war was renewed, and the following year Edward III's eldest son, the Black Prince, invaded France and won a decisive victory at the Battle of Poitiers.
Editors. "Edward III, King of England, renews war with France". The Literary Encyclopedia. First published 31 July 2012
[http://www.litencyc.com/php/stopics.php?rec=true&UID=9481, accessed 26 February 2015.]