Difficulties in raising taxes and revenue hampered the ability of the French to fight the English. At this point, the war's pace had largely slowed down, and both nations found themselves fighting mainly through proxy wars, such as during the 1383–1385 Portuguese interregnum. The independence party in the Kingdom of Portugal, which was supported by the English, won against the supporters of the King of Castile's claim to the Portuguese throne, who in turn was backed by the French.