Diego Alatriste was not a nobleman, but he was a man of honor and courage. Serving as a colonel in the Spanish army of the 17th century, he gradually became a hero in the country's imperial wars. In his personal life, he was deeply in love with the beautiful María de Castro, a famous stage actress. Alatriste also served as the guardian of the young Íñigo de Balboa, in order to keep a promise he made to the boy's father on his deathbed, while trying to raise him as a soldier according to his own wishes.