King Henry III of Castile was a monarch who ruled from 1390 to 1406. He was born on October 4, 1379, and was the son of King John I of Castile and Leonor of Aragon. His reign was marked by efforts to strengthen the monarchy and improve relations with the nobility, although he faced challenges from powerful noble families. Henry III is often remembered for his piety and dedication to the Catholic Church. He worked to promote peace within his kingdom and sought to stabilize the region during a time of political unrest. His reign laid the groundwork for future developments in Castile and the broader Iberian Peninsula.