Robert Stewart was the 2nd Marquess of Londonderry, a title he inherited from his father. He was also the 2nd Viscount Castlereagh, the 2nd Baron Londonderry, and the 1st Earl of Londonderry. He was a British statesman and diplomat who served as Foreign Secretary from 1812 to 1822.
The Castlereagh Chronicles: Unraveling the Legacy of Robert Stewart, Viscount Castlereagh