Mary and James had two sons, but both died young. Their third child, Mary Stuart, survived, but King James died six days after her birth. At first Mary and her daughter lived at Stirling Castle while the 2nd Earl of Arran acted as regent. Henry VIII wished his son Edward to marry Mary Stuart, and he was led to believe that this would happen. When it became clear that it would not, war between England and Scotland broke out. Mary of Guise sent her daughter to France to live with her husband-to-be. She initially planned to sail with her, but was called to Edinburgh for a council meeting. She then travelled to inspect the progress of a siege at Haddington, came too close to the guns, and lost sixteen of her entourage.
When the war was over, Mary returned to France for a time. While accompanying her on her return to Scotland, her son Francis died, leaving Mary Stuart as her only remaining child. Mary now began to challenge the power of Arran, and in 1554 became regent of Scotland. At first she proved a capable ruler, but soon was drawn into religious troubles as Protestantism grew more popular in Scotland. When the Protestant Elizabeth came to the English throne, things only got worse. Mary began to show less tolerance, and rebellion ensued. Mary backed up her forces with French troops, and things were going badly for the Protestants until an English fleet arrived. A treaty was reached between the Scottish and the English, and the English now joined in the siege of the French. While fortifying Edinburgh Castle, Mary became ill and died of dropsy in 1560.