'The Uncrowned King of Scotland'. Dundas was born at Dalkeith into a family distinguished for its legal and political talent. The fourth son of Robert Dundas, the 3rd Lord Arniston (1685 - 1753), he was educated at the High School of Edinburgh and then the University of Edinburgh. Dundas was elected member of Parliament for Midlothian, and later for Edinburgh. He was appointed Lord Advocate in 1777 and, under William Pitt, became Secretary of State for the Home Department in 1791. He was also Treasurer to the Navy (1782 - 1800). He wielded enormous power throughout Britain and its dominions, hence his epithet. He oversaw the expansion of British influence in India, and promoted several Scots into the ranks of the East India Company. As Secretary of State for War (1794 - 1801) he presided over the conflicts with France.
Dundas was elected Deputy Governor of the Bank of Scotland (1779) and its Governor (1790), a post he held until his death. He was also Grand Master of Scotland. He resigned with Pitt in 1801 and was made Viscount Melville and Baron Dunira (his seat near Comrie).
The town of Dundas in Ontario and the Dundas Islands near Vancouver are named after him, while he is remembered in Scotland by the immense Melville Monument in Edinburgh.