In 1837 he was active in suppressing the Canadian rebellion at the Battle of the Windmill, after which he was appointed colonel and aide-de-camp to Queen Victoria in 1841.

[2] He played a distinguished part in India as a brigadier-general in 1848–49, chosen to command the column sent from Bombay to co-operate with Lord Gough's army in the Second Anglo-Sikh War.

He was second in command at the capture of Multan and then joined the main army with his force for the battle of Gujrat.

He became Commander-in-Chief, Scotland in 1854[3] remaining in that post until 1860, in which year he was made Governor of Edinburgh Castle.

He is buried in the simple Dundas Vault in Old Lasswade Kirkyard, together with his ancestors and descendants.