The Battle of Dunbar was fought between the English New Model Army, under Oliver Cromwell, and a Scottish army commanded by David Leslie on 3 September 1650 near Dunbar, Scotland. The battle resulted in a decisive victory for the English. It was the first major battle of the 1650 invasion of Scotland, which was triggered by Scotland's acceptance of Charles II as king of Britain after the beheading of his father, Charles I on 30 January 1649.

The New Model Army or New Modelled Army was a standing army formed in 1645 by the Parliamentarians during the First English Civil War, then disbanded after the Stuart Restoration in 1660. It differed from other armies employed in the 1639 to 1653 Wars of the Three Kingdoms in that members were liable for service anywhere in the country, rather than being limited to a single area or garrison. To establish a professional officer corps, the army's leaders were prohibited from having seats in either the House of Lords or House of Commons. This was to encourage their separation from the political or religious factions among the Parliamentarians.