Castilian Civil War
The Black Prince's intervention in the Castilian Civil War, and the failure of Pedro to reward his services, depleted the prince's treasury. He resolved to recover his losses by raising the taxes in Aquitaine. The Gascons, unaccustomed to such taxes, complained. Unheeded, they turned to the King of France as their feudal overlord. But by the Treaty of Brétigny the King of France had lost his suzerainty over Aquitaine. After reflecting on the matter, it was asserted that Edward III's renunciation of France had been imperfect. In consequence, the King of France retained his suzerainty over Aquitaine. Charles V summoned the Black Prince to answer the complaints of his vassals but Edward refused. The Caroline phase of the Hundred Years' War began.