Following Oliver Cromwell's invasion of Scotland in July 1650, and the defeat of the Scots at Dunbar in September, Scotland was occupied by the New Model Army. An English garrison under General Lambert was stationed at Hamilton, in the Hieton (Scots for 'high town') area of town. Colonel Ker led a force of covenanters in a surprise attack on the garrison, but despite initial success by the rebels, the English regrouped and drove them back with heavy losses.