New step by du Guesclin: Henry II, King of Castile, 1169. Du Guesclin's White Companies once again crossed Navarre, pillaging and destroying crops and houses and even occupying some Navarrese towns such as Valtierra. After the battle of Montiel, Henry of Trastamara killed his brother Peter I (23 March 1369). It was a relief for both Navarre and Aragon to see this mystery cleared up.