Although Gascony was the cause of the war, Edward was able to spare few resources for it and when an English army had campaigned on the continent it had operated in northern France. Edward determined early in 1345 to attack France on three fronts: a small force would sail for Brittany; a slightly larger force would proceed to Gascony under the command of Henry, Earl of Derby; and the main force would accompany Edward to northern France or Flanders. In early 1345 the French decided to stand on the defensive in the south west. Their intelligence had uncovered the English plan for offensives in the three theatres, but they did not have the money to raise a significant army in each. They anticipated, correctly, that the English planned to make their main effort in northern France. Thus they directed what resources they had to there, planning to assemble their main army at Arras on 22 July. South western France was encouraged to rely on its own resources.