With seemingly positive purpose, Nithard set about extracting Spain from its ruinously expensive wars; he signed a peace treaty with Portugal in 1668 and another with France that same year. But not everyone was happy with the concessions that Nithard made, and he was overthrown by John of Austria the Younger, a general who was Charles’ illegitimate half-brother.
The next man in the seat of power was another of Mariana’s favorites, Don Fernando de Valenzuela. But in 1675 John was again the man behind the overthrow that transpired, and the 14-year-old Charles was legally eligible to take on the powers of King of Spain. However, owing to his frailty, Mariana extended her regency, also reinstating Valenzuela to a senior position.