 The Kingdom of France and the Crown of Aragon maintained a long-held rivalry for the control of Roussillon and, more recently, for hegemony in Italy.In June 1474, French troops invaded Roussillon and the Aragonese were forced to retreat.On the possibility that the heir to the throne of Aragon would also become King of Castile, Louis XI of France officially positioned himself on the side of Joanna and Afonso in September 1475.