When her husband died in October 1637, she was created regent in the name of her son Francis Hyacinth who succeeded her husband. At the death of Francis Hyacinth in 1638, her second son succeeded as Charles Emmanuel II. As a result of Charles Emmanuel's age, Christine maintained her grip on power. Despite this, her brothers-in-law, Prince Maurice and his younger brother Prince Thomas Francis disputed Christine's power as she was a woman. They also had little trust in her French entourage. When Francis Hyacinth, the brothers started the Piedmontese Civil War, with Spanish support. There were two parties. The ""principisti"", supporters of the Princes, and the ""madamisti"", the supporters of Christine. During her regency, she styled herself "Madama Reale", Italian form of the style "Madame Royale" which she was known as prior to her marriage. 