Saint Ferdinand of Castile, also known as Ferdinand III of Castile, was a Spanish king born in 1199. He is best known for his role in the Reconquista, the centuries-long effort to reclaim the Iberian Peninsula from Muslim rule. Ferdinand united the kingdoms of Castile and Leon and led successful military campaigns, capturing cities like Seville and Cordoba. Ferdinand was canonized as a saint by the Catholic Church in 1671 due to his piety and dedication to the Christian faith. He is celebrated for his commitment to justice and the welfare of his subjects, making him a revered figure in Spanish history.