"El Gran Capitán" Gonzalo Fernández de Córdoba (1453–1515)

Known as the Great Captain, was a captain-general of the armies of Castile and Aragon.
He fought in the conquest of Granada and shortly afterwards took charge of the defence of Italy against the French invasion. He created the first professional Spanish army and revolutionised the battlefield by demonstrating that infantry and firearms could defeat the mighty cavalry. In a sense, he was the ideological father of what would later become the Spanish infantry tercios.