First Battle of Olmedo

You can help expand this article with text translated from the corresponding article in Spanish. (November 2012) Click [show] for important translation instructions. View a machine-translated version of the Spanish article. Machine translation, like DeepL or Google Translate, is a useful starting point for translations, but translators must revise errors as necessary and confirm that the translation is accurate, rather than simply copy-pasting machine-translated text into the English Wikipedia. Do not translate text that appears unreliable or low-quality. If possible, verify the text with references provided in the foreign-language article. You must provide copyright attribution in the edit summary accompanying your translation by providing an interlanguage link to the source of your translation. A model attribution edit summary is Content in this edit is translated from the existing Spanish Wikipedia article at [[:es:Primera batalla de Olmedo]]; see its history for attribution. You may also add the template {{Translated|es|Primera batalla de Olmedo}} to the talk page. For more guidance, see Wikipedia:Translation.

The First Battle of Olmedo, between Castilian forces and those of Navarre and Aragon, took place on 19 May 1445 outside Olmedo in Castile (now in the province of Valladolid, Spain).

The war was in part prompted by the decrees of John II of Castile and his aide Álvaro de Luna that rents, that is taxes, from the town of Medina del Campo would be paid to his administration, rather than that of John II of Aragon, also of Navarre. The latter king invaded Castile, aided by his brother Alfonso V of Aragón. The Castilian king departed from Medina del Campo, and met the invasion at Olmedo, where he was successful. The infante (prince) Henry of Aragon, the younger brother of Alfonso and John, died of his wounds a few days later in Calatayud.