 From June–July 1378 the armies of Castile, commanded by John of Trastámara, invaded Navarre and laid the country waste.Charles II retreated over the Pyrenees to Saint-Jean-Pied-de-Port and in October he made his way to Bordeaux to plead for military aid from Sir John Neville, the Lieutenant of Gascony.Neville despatched a small force to Navarre under the knight Sir Thomas Trivet, but the English achieved little over the winter and in February Henry of Trastámara announced his son would re-invade Navarre in the spring.