New Model Army: Formation, Naseby and Civil War Victories

The New Model Army was established by Parliament in 1645 during the First English Civil War. It brought together the remaining forces of several Parliamentarian armies into a more centralised, full-time fighting force under Sir Thomas Fairfax. Its victories helped secure Parliament’s success against Charles I, while its growing political influence shaped the English Civil Wars, the establishment of the Commonwealth and the rule of Oliver Cromwell.

News, Horsemen of the New Model Army Greet a Messenger, c.1645.William Barns Wollen (1857–1936) — News, Horsemen of the New Model Army Greet a Messenger, c.1645
William Barns Wollen (1857–1936)

The New Model Army in the English Civil Wars

The creation of the New Model Army transformed Parliament’s military organisation. Earlier Parliamentarian forces had often been raised and maintained by regional associations, with commanders and local authorities exercising considerable control. The new army was designed to provide a more coordinated national force capable of sustained campaigning. Its formation was an important development in the military and political history of the Wars of the Three Kingdoms.

Why was the New Model Army formed?

By 1644, Parliament had struggled to turn its military resources into a decisive victory. Its armies operated under different commanders and were often affected by disagreements over strategy, recruitment and the allocation of supplies. The Royalists remained capable of winning battles and threatening Parliamentarian strongholds.

The victory at Marston Moor in July 1644 demonstrated the value of cooperation between Parliamentarian and Scottish forces, but it did not end the war. Parliament’s leaders concluded that military reorganisation was necessary if Charles I was to be defeated.

The Self-Denying Ordinance and the New Model Army Ordinance of early 1645 formed part of this reform. The new arrangements aimed to reduce the influence of political and personal rivalries among commanders and create a more unified military organisation. The army was intended to serve Parliament’s war effort rather than the interests of individual regions or commanders.

Organisation and command

The New Model Army was organised as a full-time force of cavalry, infantry and dragoons. Its intended establishment was approximately 22,000 men, including around 6,000 cavalry, 14,400 infantry and 1,000 dragoons. Recruitment, supply and pay were organised on a more centralised basis than in many of Parliament’s earlier forces.

Sir Thomas Fairfax was appointed commander-in-chief. Oliver Cromwell, who had already established a reputation as a cavalry commander, became lieutenant-general of horse during the army’s first major campaign. Other experienced officers also served in its command structure.

The army’s officers were not selected exclusively on the basis of aristocratic rank. Military experience, ability and commitment to Parliament’s cause could contribute to advancement. However, the army was not socially uniform: officers still included members of the gentry, and soldiers came from a variety of backgrounds.

Training, discipline and equipment

The New Model Army was intended to operate as a coordinated force, with regular service, central organisation and established chains of command. Its effectiveness depended on maintaining discipline, keeping soldiers supplied and coordinating infantry and cavalry in battle.

Cavalry played a particularly important role. Parliamentarian horsemen could charge, regroup and return to the fighting rather than automatically pursuing a retreating enemy. At Naseby, the cavalry commanded by Cromwell helped turn the battle against the Royalists after defeating their opponents on the Parliamentarian flank.

Uniforms and equipment varied, and it is misleading to imagine every soldier wearing an identical outfit. Red coats became associated with Parliamentarian forces, but clothing, armour and weapons differed according to regiment, rank, availability and military role. Both sides in the English Civil Wars used combinations of pikes, firearms, swords and protective equipment.

The Battle of Naseby, 1645

The New Model Army’s first major test came at the Battle of Naseby on 14 June 1645. Fairfax commanded the Parliamentarian army against the Royalist forces led by Charles I. Cromwell commanded the Parliamentarian cavalry on the right wing.

The Royalist cavalry initially achieved success on their left, but their pursuit of opposing horsemen took them away from the main battlefield. Cromwell’s cavalry defeated the Royalist horse on the opposite wing and then attacked the Royalist infantry. Fairfax’s infantry came under heavy pressure during the fighting, but the Parliamentarian army ultimately prevailed.

The Royalists suffered a decisive defeat, losing much of their field army and substantial quantities of equipment and supplies. The capture of the king’s correspondence also provided Parliament with material that damaged the Royalist cause. Naseby marked a turning point in the First English Civil War.

The campaigns of 1645–1646

After Naseby, the New Model Army continued campaigning against Royalist forces and strongholds. Parliamentarian operations in the west and south-west reduced the territory remaining under royal control. Bristol surrendered to Parliament in September 1645, while other Royalist positions fell during the following months.

Oxford, one of the king’s principal centres, remained in Royalist hands until 1646. Charles I left the city in April and surrendered to the Scottish army at Newark in May. The remaining Royalist strongholds subsequently surrendered or were reduced, bringing the principal fighting of the first war to an end.

The New Model Army’s success did not settle the political future of the kingdoms. Disagreement continued over the king’s position, the future of the army, religious policy and the settlement Parliament should impose. The military victory therefore opened a new phase of political conflict.

The New Model Army and the Second English Civil War

After the first war, the army became increasingly involved in disputes over the settlement with Charles I. Soldiers and officers were concerned about arrears of pay, proposals to disband the force and the possibility that political opponents might impose a settlement that ignored their interests.

Political divisions also developed within the army. Some soldiers and officers supported more radical proposals for political representation and religious liberty, while others favoured a more limited constitutional settlement. The Levellers became associated with demands for political reform, although the army as a whole did not share a single political programme.

Renewed Royalist resistance and the Scottish alliance with Charles I led to the Second English Civil War in 1648. The New Model Army helped defeat Royalist forces, including at the Battle of Preston. After the fighting, the army’s senior leadership increasingly opposed a settlement that would restore Charles I to power without resolving the causes of conflict.

The army, the trial of Charles I and the Commonwealth

The army’s political influence grew during 1648. In December, soldiers under Colonel Thomas Pride excluded a number of MPs from the House of Commons in an action known as Pride’s Purge. The reduced Parliament subsequently arranged the trial of Charles I.

The king was executed in January 1649, and the monarchy and House of Lords were abolished. The new republican government, known as the Commonwealth, relied heavily on military power to maintain its authority.

The army also faced internal opposition. In 1649, Leveller-influenced soldiers mutinied at Bishopsgate and Burford. The leadership suppressed the mutinies, and several soldiers were executed. These events demonstrated that the army’s political and religious diversity could lead to serious internal divisions.

Ireland, Scotland and the army’s expanding role

In 1649, the New Model Army was sent to Ireland under Oliver Cromwell as part of the Commonwealth’s campaign to establish control. The sieges of Drogheda and Wexford involved large-scale killings, including the deaths of defenders and civilians. The campaign was followed by further military operations and a major transformation of landholding and political authority in Ireland.

The army also played a central role in the conflict with Scotland. Following the proclamation of Charles II as king by the Scots, Cromwell led the English army into Scotland in 1650. The victory at Dunbar in September 1650 and the defeat of the Scottish army at Worcester in September 1651 secured the Commonwealth’s military position, although resistance and occupation continued.

These campaigns extended the army’s responsibilities well beyond the defeat of Charles I. Its soldiers became central to the enforcement of the republican government’s authority across the British Isles.

The New Model Army and Oliver Cromwell’s Protectorate

The army remained a major political force after the establishment of the Commonwealth. Disputes between military leaders and Parliament contributed to the dissolution of the Rump Parliament in 1653 and the subsequent establishment of the Protectorate.

Under Cromwell, military officers held important administrative responsibilities, and the army supported the regime during periods of political instability. The Major-Generals system introduced in 1655 gave senior officers responsibility for regional security and aspects of local government. This strengthened military involvement in civilian affairs and attracted opposition.

The army was not politically united, however, and its leaders disagreed over the constitution, religious policy and the future of government. After Cromwell’s death in 1658, these divisions contributed to the instability that brought the Protectorate to an end.

The New Model Army and the Restoration

The army continued to influence events after Richard Cromwell resigned as Lord Protector in 1659. Political and military factions struggled to establish a workable government, and the army’s divisions made a stable settlement increasingly difficult.

General George Monck’s intervention helped create the conditions for the restoration of Charles II in 1660. The return of the monarchy ended the republican experiment, but the experience of the New Model Army had demonstrated the extent to which a national military force could influence political power.

The significance of the New Model Army

The New Model Army was central to Parliament’s victory in the First English Civil War and remained a decisive force in the conflicts that followed. Its organisation, regular service and centralised command helped Parliament sustain military campaigns and defeat the Royalists.

Its history also shows how military institutions can become involved in political struggles. The army helped bring about the execution of Charles I, supported the Commonwealth and Protectorate, and ultimately became part of the unstable political circumstances that led to the Restoration. Its legacy belongs to both the military history of the English Civil Wars and the wider history of government in the three kingdoms.

The New Model Army