From 1592, Christina was the second wife of Duke Charles of Södermanland. Following his accession as Charles IX in 1604 she became queen, although the two were not crowned until three years later. Christina was the mother of Gustav II Adolf, and for a few months in 1611 she led the regency for her son. As dowager queen she had Gripsholm as her dower house. Christina vigorously defended her personal interests against the power of the Crown.