The Battle of Benburb, 1646

The papal nuncio Archbishop Rinuccini, who arrived in Ireland in November 1645, brought supplies of arms, ammunition and money provided by Catholic well-wishers in Europe to assist the Confederate war-effort. Regarding Major-General Robert Monro's Covenanters in Ulster as the main threat to the Confederacy, the Supreme Council granted funds to Owen Roe O'Neill that enabled him to equip a full field army for the first time in the war. The strength of O'Neill's army was about 5,000 foot, half of whom were pikemen and half musketeers, and 500 horse, many of whom were lancers. The Irish had no artillery available. O'Neill mustered his forces at the hill of Gallanagh near Lough Sheelin on the Cavan-Westmeath border and marched north on 31 May 1646.

Campaign map of Benburb 1646
Manoeuvres before Benburb, May-June 1646

As O'Neill marched towards Ulster, Major-General Monro advanced westwards from his winter quarters in Down and Antrim. He had over 6,000 men, made up of six Scottish and four English regiments of foot and around 600 horse. Monro's infantry was two-thirds musketeers and one-third pikemen. Like O'Neill, his cavalry contained a large number of lancers, but Monro also possessed six pieces of field artillery. Monro's immediate objective was to join forces at Glaslough with two further British units: a force of around 240 musketeers and 100 horse commanded by his son-in-law Colonel George Monro that was marching south from Coleraine in County Londonderry, and 2,000 men of the Lagan army advancing eastwards from the Foyle valley. Monro was probably planning to advance into Confederate territory in Leinster, while the Lagan army marched south-westwards into Connacht to join forces with other Lagan units that were supporting Sir Charles Coote in County Sligo.

On 4 June, Monro was camped at Poyntz Pass to the north of Newry from where he sent a cavalry detachment ahead to locate the Coleraine column. The British detachment encountered scouts from O'Neill's army near Armagh and took a prisoner who informed them of the strength of the approaching Irish army. Monro immediately ordered a forced march to Armagh, hoping to take the Irish by surprise. However, O'Neill was aware of the converging British forces and had already crossed to the north bank of the River Blackwater to occupy a strong position at Benburb with the river to shield him from Monro's main force and the Confederate stronghold of Charlemont behind him to fall back on if necessary. O'Neill next ordered Lieutenant-Colonel Brien Roe O'Neill to take most of the Irish cavalry and a small party of foot northwards towards Dungannon to intercept the Coleraine column.

With the crossings of the Blackwater at Benburb and Charlemont strongly defended, Monro was forced to march five miles upstream to the ford at Caledon and then to march along the north bank of the Blackwater to reach O'Neill's position. The British troops were already tired after their forced marches from Poyntz Pass and Armagh, but crossed the river at about three o'clock in the afternoon of 5 June 1646. Although the Lagan force was too far away to participate in any action, Monro expected O'Neill to withdraw to Charlemont as the main British force and the Coleraine column converged on Benburb. However, O'Neill was determined to meet the British in a pitched battle. He sent skirmishers to disrupt and delay Monro's advance along the river bank so that Brien Roe's detachment would have time to deal with the Coleraine column. It was early evening when Monro's exhausted troops finally came face-to-face with the Irish.

The battle of Benburb

O'Neill's army was drawn up in two lines, with four infantry brigades in the front line and three in the second, arranged in files six to nine men deep. A small reserve of musketeers was at the rear and the remaining cavalry were on the wings in squadrons three or four deep. The Irish position was chosen to restrict Monro's deployment to a small hill where the British had little room to manoeuvre, with the River Blackwater on their right flank and boggy ground on the left. The British infantry also deployed in two lines, with five brigades in each. Because of the constraints of the ground, the British cavalry was drawn up behind the infantry, ready to charge through the gaps between the brigades. Monro's six field guns were placed in front of the infantry. A small stream ran between the two armies into the Blackwater.

The battle opened with a cannonade from Monro's artillery, then Viscount Montgomery led a force of horse and musketeers to take control of a ford across the brook that separated the two armies. Irish skirmishers advanced to contest the crossing and the British were driven back by a cavalry charge from O'Neill's left flank. This was followed by a stand-off, with the British guns continuing to fire into the ranks of the Irish. At this point, Brien Roe's cavalry returned. They had surprised and routed the Coleraine column near Dungannon and hurried back to rejoin the main Irish army. With his lines now complete and no danger of British reinforcements arriving, O'Neill prepared to attack. Father MacEgan, the chaplain-general of the army, delivered a general absolution and O'Neill exhorted his men to wreak vengeance on the British, who had persecuted them for their religion and driven them from their Ulster homelands.

The general Irish advance began at about eight o'clock in the evening. Monro's cavalry charged in an attempt to break up the Irish brigades but their horses were exhausted from the long marches of the previous two days and the attack was ineffective. Advancing relentlessly, the Irish overran the British artillery positions and came to push of pike with Monro's front line of infantry. There followed an hour or more of grim fighting. The tightly packed British infantry were piled in on top of one another. A second British cavalry charge failed to disrupt the Irish lines, then O'Neill ordered Colonel Farrell to work around and attack Monro's left flank. The whole British line was slewed around and forced back towards the river. The cavalry fled and, as darkness began to fall, the British position collapsed in confusion.

Up to 3,000 British were killed in the battle and the rout that followed. Major-General Monro was lucky to escape the slaughter. The British lost their artillery, most of their weapons and their baggage train. Irish losses were around 300 men killed. Benburb was the biggest set-piece battle of the Confederate War. It was celebrated by Rinuccini at Kilkenny and the Pope in Rome, both of whom expected that it would lead to the liberation of Catholic Ireland. Two days later, O'Neill followed up his victory by advancing towards Clones and chasing the Lagan army back to its strongholds in counties Derry, Donegal and Tyrone, leaving the Confederates with the only army in the field in Ulster.


S.R. Gardiner, History of the Great Civil War, vol.iii, (London 1889)

G.A. Hayes-MacCoy, Irish Battles, a military history of Ireland, (London 1969)

Pádraig Lenihan, Confederate Catholics at War 1641-49, (Cork 2001)

Jane Ohlmeyer, The Civil Wars in Ireland (in The Civil Wars, a military history of England, Scotland and Ireland 1638-60), Oxford 1998