Despite being outnumbered and exhausted after riding overnight from Oxford, a Royalist cavalry force under Lord Wilmot won a crushing victory over the Parliamentarian Army of the West under Sir William Waller.

[8] As the Parliamentarians approached, Hopton marched south to Devizes, followed by Waller who occupied Roundway Down, high ground approximately 2 kilometres north of the town.

Short of materials and outnumbered, the Royalists agreed that Prince Maurice and 300 cavalry would break out and race to Oxford for reinforcements, leaving Hopton and the 3,000 Cornish foot to hold Devizes.

[3][5] On the morning of 12 July, Waller ended talks and began an assault, first bombarding the town with artillery before his infantry attacked the outworks and fortifications.

[2] As Waller advanced down the hill, Byron continued his attack supported by Wilmot and the Royalist reserve under Crawford; with their infantry unable to fire for fear of hitting their own men, the Parliamentarian cavalry were swept from the field.

After approximately an hour, Byron’s cavalry returned from their pursuit and captured the Parliamentarian artillery which they turned on the retreating enemy, quickly causing them to break apart.

[16] Arguably the most comprehensive Royalist victory of the war, it secured the south-west and less than two weeks later they captured the vital port of Bristol, allowing them to establish links with their supporters in Ireland.