"Marquess of Londonderry" . . . . "half-siblings" . . "Marquess of Londonderry" . . "1739" . "Robert Stewart, 1st Earl of Londonderry" . . "1st Marquess of Londonderry" . . "Robert
'''1st
Marquess'''" . "1821" . "Robert Stewart, 1st Marquess of Londonderry" . "Robert Stewart" . . . . . . . "Robert Stewart, Baron Londonderry" . "Robert Stewart, Earl (1796), and later Marquess (1816), of Londonderry" . . . . "The Earl of Londonderry" . . . "Robert Stewart, 1st Marquess of Londonderry" . . . . . . . "The Marquess of Londonderry" . . "Robert Stewart, 1st Viscount Castlereagh" . . . . . . . . . . . . . "Robert Stewart, 1st Marquess of Londonderry, 1st Earl of Londonderry, 1st Viscount Castlereagh, 1st Baron Londonderry" . . "The 1st Marquess of Londonderry" . . . "Earl of Londonderry" . "Robert Stewart, 2nd Marquess of Londonderry" . . . "the first Marquess of Londonderry" . . . "Robert" . "Robert
'''1st
Marquess'''" . . "Lord Londonderry" . .