Dundas was born in Edinburgh to Elizabeth and James Dundas. He schooled at Westminster
and Oxford, where he received his BA in
1820, and his MA two years later. Dundas's life was a blend of law and politics, and by
1840, he was appointed to the Queen's Council. On
10 July 1846, he became solicitor-general under
Lord John Russell. Dundas was knighted on 4 February,
1847, but would resign from office due to inconstant health in
March of 1848. A more comfortable post was offered, as principal clerk of the House of Lords, but
Dundas declined the position. He took office again in
May of 1849 as judge-advocate-general; thereafter, he was sworn into the privy council on June
29th of the same year. He retired from political life altogether in
1852.
In his role as Solicitor General, Dundas, along with Attorney General
John Jervis, was instrumental in the Crown's deliberations on the
Hudson's Bay Company's land-grant status following the
Oregon Treaty of
1846. The two men signed-off on a
Case,
attached to an
1847 despatch, that detailed the complex legal arguments surrounding the
HBC's position.