Unlike France, the kingdom of Spain had no Salic Law, so it was possible for a female to assume the throne. When Maria Theresa's brother Balthasar Charles died in 1646, she became heir presumptive to the vast Spanish Empire and remained such until the birth of her brother Philip Prospero, in 1657. She was briefly heir presumptive once more between 1–6 November 1661, following the death of Prince Philip and until the birth of Prince Charles, who would later inherit the thrones of Spain as Charles II.