One ruler of this region enlisted the help of Edward the Black Prince at the Battle of Najera and defeated his half-brother Henry Trastamara to regain the throne.
One count of this region killed his brother-in-law Vermudo III at the Battle of Tamaron. One army from this region was routed at the Battle of Alarcos. One ruler of this region enlisted the help of Edward the Black Prince at the Battle of Najera and defeated his half-brother Henry Trastamara to regain the throne. That ruler fought Peter IV in the "War of the Two Peters." This region was home to (*) Peter the Cruel, and a succession crisis in this region included the Battle of Toro and concluded with the Treaty of Alcacovas. That crisis was brought about after Afonso V claimed the throne of this place, accusing queen Joan of having an affair. Another ruler of this region came to power with the death of Henry IV and was the daughter of John II. For 10 points, name this region of central Spain which was united with Aragon by the wedding of Ferdinand and Isabella.
One count of this region killed his brother-in-law Vermudo III at the Battle of Tamaron.
Kingdom of Castile [or Castille]