The Battle of Roundway Down, 1643

Despite the marginal Royalist victory at Lansdown Hill, Lord Hertford's army was in low spirits owing to heavy casualties, the death of Sir Bevil Grenville and serious injuries to Sir Ralph Hopton. Most of the Royalist cavalry had scattered during the battle and the army was short of supplies and ammunition. After regrouping at Marshfield, the Royalists marched towards Oxford, halting for two days at Chippenham in Wiltshire. Meanwhile, Sir William Waller summoned reinforcements from Bristol and set off in pursuit of the battered Royalist army with an overwhelming force of nearly 5,000 men.

The Siege of Devizes, 9-13 July 1643

On 9 July, Waller's advance guard of cavalry caught up with the Royalists and attacked them as they approached Devizes. Prince Maurice's cavalry and Lord Mohun's regiment of foot fought a rearguard action at the village of Rowde that held off the Parliamentarians and gave the Royalist infantry time to get into the town. At a council of war on 10 July, Sir Ralph Hopton agreed to defend Devizes with the infantry and artillery while Prince Maurice rode to Oxford for reinforcements with Lord Hertford and Lord Carnarvon. Maurice broke out at midnight with 300 cavalry, riding south-east to evade Waller's patrols before turning north for Oxford.

The Roundway Down campaign

Prince Maurice and his companions rode the forty-five miles from Devizes to Oxford in a single night. When they arrived, they found that most of the Oxford army was in the Midlands with Prince Rupert and the Queen. A convoy of gunpowder and ammunition had been sent to re-supply the Western Army after Lansdown under the command of the Earl of Crawford, but troopers of Waller's own regiment of horse under Major Dowett ambushed the convoy on 11 July. The Royalist cavalry escort was scattered and the convoy captured. While no infantry could be spared from Oxford, a relief force of 1,500 horse was detached under the command of Lord Wilmot, supported by Sir John Byron and the Earl of Crawford. Prince Maurice, Lord Carnarvon and the 300 horse that had ridden from Devizes also joined the column. Two brass field guns and a supply of gunpowder and ammunition were requisitioned. The relief force rendezvoused at Marlborough on 12 July and approached Devizes on the afternoon of the following day.

Meanwhile at Devizes, Waller had deployed his forces on the eastern side of the town and set up a battery on Coatefield Hill. Sir Ralph Hopton initiated treaty negotiations on 11 July, which gained a day's respite, but Waller suspected that he was playing for time and proceeded with preparations for an assault. Although short of gunpowder and ammunition, the Royalists set up their artillery in the remains of Devizes Castle, barricaded the streets with tree trunks and carts, and lined the hedgerows and embankments around the town with musketeers. The Parliamentarians attacked on the morning of 12 July, supported by artillery fire from Coatefield Hill. The Royalists resisted fiercely; although some of the outworks were overrun, the main Parliamentarian attack was repulsed.

The battle of Roundway Down, 13 July 1643

Waller was planning further attacks on Devizes when his scouts reported the approach of Wilmot's relief force during the morning of 13 July. Waller drew off his entire army and regrouped on Roundway Down to the north of Devizes, leaving a few troops to guard his artillery and baggage wagons. The Parliamentarian army consisted of around 2,500 foot and between 2,500 and 3,000 horse and dragoons, supported by eight field guns. Waller deployed his troops conventionally, with five regiments of foot in the centre guarded by cavalry on each flank and artillery covering the gaps between. The Parliamentarian army was double the size of the Royalist relief force, which consisted of 1,800 horse with no infantry. Wilmot hoped that Hopton would send out the 3,000 Royalist foot stationed in Devizes to support his cavalry, but Hopton was persuaded to delay by his officers, who suspected that Waller's withdrawal was a stratagem to tempt them to leave the town.

Wilmot deployed the Royalist cavalry in three brigades. He personally led the brigade on the right while Sir John Byron commanded on the left. The Earl of Crawford kept a third brigade in reserve.

The battle began at about 3 o'clock in the afternoon of 13 July. As the Royalists moved forward, a Parliamentarian forlorn hope advanced to harass them. Major Paul Smith of Wilmot's regiment led a Royalist forlorn hope to counter-attack, and the Parliamentarians were thrown back. Sir Arthur Heselrige on the Parliamentarian left wing advanced his formidable cuirassier regiment to support the fleeing troopers. Heselrige's troops were arrayed six deep in close order; his charge was met by Wilmot's brigade which advanced at a trot three deep in extended order. When the opposing ranks met, Wilmot's line overlapped Heselrige's and the Parliamentarians gave ground. Heselrige rallied his men for a second charge but seeing the second Royalist brigade ready to support Wilmot, the cuirassiers broke away and fled.

With Heselrige's Lobsters routed, Sir William Waller advanced with the right wing of horse flanking his infantry. Byron's brigade charged Waller's horse, steadfastly ignoring the covering fire from the Parliamentarian foot and artillery. Byron ordered his troopers not to fire their pistols until they were among the Parliamentarian horse. Supported by Lord Crawford's reserve, Byron swept the Parliamentarian right wing from the field. The triumphant Royalists pursued the fleeing Parliamentarian cavalry, a number of whom were driven over the edge of a precipitous slope on the edge of Roundway Down.

The Parliamentarian infantry were left stranded. Their cavalry were routed but Waller remained on the field and formed the infantry into defensive squares. For over an hour, the Parliamentarians fended off attacks by Wilmot's cavalry. The attacks became heavier as more Royalist horse returned to the field. When the 3,000 Cornish infantry finally marched out of Devizes and advanced towards the battlefield, Waller ordered a retreat eastwards.

The Parliamentarian infantry began to march off in good order but lost cohesion when Byron's men opened fire on them with captured cannon and advanced to attack. In the confusion, Waller and his mounted officers galloped away towards Bristol. The withdrawal became a rout as the Parliamentarian infantry ran for the wooded eastern slopes. Hundreds were cut down or taken prisoner, many dying in an area still known as Bloody Ditch at the foot of the hillside. All Waller's artillery, ammunition and baggage was taken. Parliament's entire Western Association army had been wiped out in the most sweeping victory of the civil wars.