The ancient lands of the Dundas family are those of the 'South Fort' or 'Dun Deas', lying close to South Queensferry. The family descend originally from Northumbrian nobility.
The main branch is Dundas of Arniston, the members of whom became noted lawyers and include Henry Dundas, Viscount Melville (1742 - 1811), the most powerful politician of his time.
The Dundas of Fingask branch originated in 1364, when John of Dundas was granted a charter to the lands of Fingask (near Rhynd in Perth and Kinross) by King David II. This branch of the family includes the merchant Sir Lawrence Dundas (1712-81) and was the ancestors of the Earls of Zetland, who are now based in Yorkshire (England).