Alliance between Castile and France

Timeline

1. 1379Castilian court (Burgos–Torrelobatón) · CastileBefore his death in 1379, Henry II had already planned a renewed invasion of Navarre; John I succeeded him, inheriting the Trastámara family's anti-English stance with France. After the Bruges truce expired in 1377, Jean de Vienne had already gone to Castile to discuss joint naval operations. The new king confirmed continued provision of galleys to France to counter English superiority in Gascony and the Channel.
2. 1379Navarre and the Bay of Biscay · NavarreIn 1379 Castile and Navarre signed the Treaty of Briones, forcing Charles II to ally with Castile and expel English troops from his realm. France used the Castilian navy to harass England at sea, continuing the strategic cooperation since the 1372 victory at La Rochelle. John of Gaunt's claim to the Castilian throne further complicated the Anglo-French-Iberian triangle, paving the way for the joint Franco-Castilian fleet's 1380 raid on England's southern ports.