Castilian Civil War
The Black Prince (Edward, Prince of Wales and Duke of Aquitaine) was the main beneficiary of the peace treaty of 1362 between England and Castile that allowed Castile to keep safe maritime trade routes and in turn England kept herself safe from the large Castilian war fleet. Edward did not seem interested in prohibiting the participation of his Gascon and English subjects in the Castilian Civil War on the side of the pretender Henry, although it favoured France and was against the interests of England. Aquitaine was going through a difficult stage as the main funding sources for this traditionally poor region were the wine industry, which was depressed and warfare. Aquitaine no longer received subsidies from England and needed other sources of revenue.