Queen Isabella died in late 1504, and Philip and Juana went to Castile to claim the crown. Their eldest son stayed behind, for the Burgundians refused to accept him as their ruler unless he was brought up in the Low Countries. After Philip's death, the House of Habsburg entered a new crisis: Charles was the new sovereign of the Low Countries, but he was young and alone. Juana could not return to act as regent because her unstable mental state and her Castilian subjects would not allow their ruler to abandon the kingdom. With Charles too young to govern, the provinces of the Low Countries voted to make Maximilian their regent. Preoccupied with his affairs in Germany, the now Emperor named Margaret governor of the Low Countries and guardian of Charles in 1507, along with her nieces Eleanor, Isabella and Mary. She became the only woman elected as its ruler by the representative assembly of Franche-Comté, with her title confirmed in 1509.