Its strong stone walls, which survived both fires in the 16th century, sheltered rooms that were occupied by Mary Stuart and her second husband, Lord Darnley, in the 1560s.
The fires were set by the servants our of hate. 
mnli hypothesis: The fires were set by the servants our of hate.  premise: Its strong stone walls, which survived both fires in the 16th century, sheltered rooms that were occupied by Mary Stuart and her second husband, Lord Darnley, in the 1560s.