Various, Encyclopaedia Britannica, 11th Edition…
“ LONDONDERRY, ROBERT STEWART, 2nd Marquess of (1769-1822) , British statesman, was the eldest son of Robert Stewart of Ballylawn Castle, in Donegal, and Mount Stewart in Down, an Ulster landowner, of kin to the Galloway Stewarts, who became baron, viscount, earl and marquess in the peerage of Ireland. The son, known in history as Lord Castlereagh, was born on the 18th of June in the same year as Napoleon and Wellington. His mother was Lady Sarah Seymour, daughter of the earl of Hertford. He went from Armagh school to St John’s College, Cambridge, but left at the end of his first year. ”
