like him a descendant of Margaret Tudor and Henry VII. Mary's descent from Margaret Tudor's first marriage to James IV of Scots also placed her in line for the English throne, but many argued that Margaret Douglas's claim was superior as Margaret and her sons Henry Stuart, Lord Darnley and Charles Stuart, 1st Earl of Lennox had been born in England. According to English custom it is desirable that the monarch be naturalized or born in England. By marrying Darnley, Mary neutralized a dangerous rival claim to the throne of England whilst strengthening that of her own house. In 1603 Mary and Darnley's son, James VI of Scotland, succeeded Elizabeth I as King of England, thereby uniting the crowns of England and Scotland and laying the basis for the future United Kingdom. See also Duke of Aubigny Duke of Richmond Duke of Lennox Earl of Lennox Auld Alliance References House of Stuart Scottish families