The marquessate expired following the death of the 5th and last Marquess.
Lady Dufferin inherited a considerable fortune at the time, not least due to the Guinness connection.
She also inherited the beautiful Clandeboye Estate, near Bangor, County Down, and a London residence in Holland Park.
Clandeboye Estate comprises about 2,000 acres of prime Ulster woodland and gardens, making it one of the finest private country estates in Northern Ireland.
Lady Dufferin had a great passion the Arts, painting and conservation.
Clandeboye Golf Club has now become an integral part of the estate.
There is a memorial to the 1st Marquess in the grounds of Belfast City Hall.
I have written an article in April, 2009, entitled The Four Great Ulster Marquessates.
First published in August, 2009. Dufferin arms courtesy of European Heraldry.