Mary Queen of Scots This is biography of Mary Stuart of Scotland, was queen of Scotland from 1542 to 1567. Mary the only surviving legitimate child of King James V of Scotland. In 1567, she was forced to abdicate in favor of James, her one-year-old son. After an unsuccessful attempt to regain the throne, she fled southwards seeking the protection of her first cousin Queen Elizabeth I of England. Mary had previously claimed Elizabeth's throne as her own. Perceiving her as a threat, Elizabeth had her confined in a number of castles. After eighteen and a half years in custody, Mary was found guilty of plotting to assassinate Elizabeth, and was subsequently executed.