The Kingdom of Castile had signed a peace treaty with the Nasrid dynasty who controlled the Emirate of Granada.

[1] Muhammad VII, encouraged and aided by the Marinid Dynasty of Morocco, invaded the territory of Murcia.

Henry III of Castile, who had completed a series of battles against Portugal, saw his opportunity to counter the Granadan threat after signing a peace treaty with the Portuguese in 1402.

One of the more famous Castilian knights that participated in this campaign was Juan de Tovar y Toledo, who was given land and title in part for his actions at Collejares.

Henry III moved against Granada, the last Muslim stronghold on the Iberian Peninsula after centuries of Reconquista.