The <a href="https://en.wikipedia.org/wiki/Second_Battle_of_Olmedo" id="mwQA" rel="mw:WikiLink" title="Second Battle of Olmedo">Second Battle of Olmedo</a> takes places as part of a succession conflict between <a href="https://en.wikipedia.org/wiki/Henry_IV_of_Castile" id="mwQQ" rel="mw:WikiLink" title="Henry IV of Castile">Henry IV of Castile</a> and his half-brother <a href="https://en.wikipedia.org/wiki/Alfonso,_Prince_of_Asturias_(1453–1468)" id="mwQg" rel="mw:WikiLink" title="Alfonso, Prince of Asturias (1453–1468)">Alfonso, Prince of Asturias</a>.