Between 1290 and 1513, the kingdom of Scotland was almost continuously at war with England. The wars began with the attempts of the first three Edwards to conquer Scotland. But they continued long after those attempts had failed. The main reason for this was the involvement of Scotland as an ally of France in the bitter Anglo–French conflict known as the Hundred Years’ War. It is not often realised that the first hostilities of the Hundred Years’ War, in 1336, arose from the refusal of Edward III of England to comply with a French ultimatum to withdraw his armies from Scotland. Thereafter, Scottish raids into England were regularly co-ordinated with the French so as to coincide with English attacks on France. The situation was aggravated by the growth in the Scottish and English borderlands of a society increasingly dependent on war for its livelihood. This was a particularly significant factor in Scotland during the half-century from the 1370s to the 1420s when the Border was dominated by the Black Douglases.