John of Austria

John of Austria (Spanish: Juan, German: Johann; 24 February 1547 – 1 October 1578) was the natural son born to Holy Roman Emperor Charles V late in life when he was a widower. Charles V met his son only once, recognizing him in a secret codicil to his will. John became a military leader in the service of his half-brother, King Philip II of Spain, Charles V's legitimate heir, and is best known for his role as the admiral of the Holy Alliance fleet at the Battle of Lepanto.