Irish Rebellion of 1641: Uprising in Ulster and Its Aftermath

The Irish Rebellion of 1641 was a rising by Catholic Irish gentry that broke out in Ulster on 22–23 October 1641. A plan to seize Dublin Castle was betrayed, but in the north the rising spread rapidly, and Protestant settlers were robbed, expelled and in many places killed. The rebellion opened more than a decade of war in Ireland, poisoned relations between Catholics and Protestants for centuries, and was one of the sparks of the civil wars in England and Scotland.

Background: land, religion and fear

By 1641 the majority of Ireland’s population was Catholic, but political power and an increasing share of land lay with Protestants. The Plantation of Ulster after 1609 had transferred much of six northern counties from Gaelic Irish owners to English and Scottish settlers. Smaller plantations followed elsewhere, and many Catholic landowners feared they would be next.

The native Irish were not the only discontented group. The “Old English”, Catholic descendants of medieval settlers, had been loyal to the Crown but resented religious penalties and insecure land titles. Thomas Wentworth, later Earl of Strafford, who governed Ireland from 1633 to 1640, alienated almost every interest by challenging land titles and raising revenue aggressively.

The wider British crisis made matters worse. The Scottish Covenanters had defied Charles I in the Bishops’ Wars of 1639–1640, and the Long Parliament in London was strongly anti-Catholic. Irish Catholics feared that a Puritan-dominated Parliament would impose harsher laws on their religion. Some plotters believed that a rising would put them in a strong bargaining position, while also presenting themselves as loyal to the king.

The plot and the outbreak

The conspiracy was organised during 1641 by a group of Ulster and Leinster gentry, including Rory O’More, Connor Lord Maguire, Hugh Óg MacMahon and Sir Phelim O’Neill. They planned to seize Dublin Castle, with its arms store, on 23 October while other groups took forts and towns in Ulster.

On the evening of 22 October, Owen O’Connolly, a Protestant servant, informed the Lords Justices in Dublin. Maguire and MacMahon were arrested, and the capital was secured. In Ulster, however, the rising went ahead. Sir Phelim O’Neill took Charlemont fort and Dungannon on the night of 22 October, and within days the rebels held much of Armagh, Tyrone, Monaghan, Cavan and Fermanagh.

In early November O’Neill claimed to be acting under a commission from Charles I. The document was almost certainly a forgery, but the claim was widely repeated and damaged the king’s reputation in England and Scotland.

Violence against the settlers

The leaders had intended a limited rising, but control quickly broke down. Settlers were stripped of goods, clothing and livestock and driven from their homes in winter. Killings began within weeks and became more frequent as rebel attacks on towns such as Drogheda and Lisburn failed.

The most notorious incident took place at Portadown in November 1641. A group of Protestant prisoners, usually estimated at around 100 people, were forced off the bridge into the River Bann and drowned or were shot. Other killings occurred at places such as Kilmore in County Armagh and, in February 1642, at Shrule in County Mayo.

Historians now generally estimate that about 4,000 settlers were killed directly. Several thousand more, perhaps up to 8,000, may have died of exposure, hunger and disease after being expelled. Violence also ran the other way: government forces and later Scottish troops killed many Catholic civilians, for example on Islandmagee in County Antrim in early 1642.

Propaganda and the numbers

News of the rising reached London in November 1641 and was soon wildly exaggerated. Pamphlets illustrated with woodcuts and engravings described mass murder in lurid detail. Many claimed that 100,000, 150,000 or even more Protestants had been killed, figures far higher than the entire settler population of Ulster.

Sir John Temple’s book “The Irish Rebellion”, published in 1646, gave these claims an official tone and was reprinted for generations. Such accounts shaped English attitudes for decades and were cited to justify Oliver Cromwell’s harsh campaign in Ireland in 1649–1650.

The main documentary record is the 1641 Depositions, roughly 8,000 statements collected from witnesses, mostly Protestant, by government commissioners. They contain first-hand testimony but also hearsay and rumour, and historians use them with care. They are held at Trinity College Dublin and were published online in 2010.

From rising to war

The rebellion soon became national. In late November 1641 Irish forces defeated a government column at Julianstown, and in December many Old English lords of the Pale joined the rebels. By 1642 the rising had turned into a war fought across the island.

In 1642 Irish Catholic leaders set up the Confederation of Kilkenny, a provisional government that ruled much of Ireland for most of the 1640s and declared loyalty to Charles I. A Scottish army under Robert Monro landed at Carrickfergus in April 1642 to protect the Ulster settlers. Parliament’s Adventurers’ Act of 1642 raised money from investors on the promise of Irish land to be confiscated once the rebellion was defeated.

The rebellion also had a direct effect in England. Everyone agreed an army was needed, but Parliament did not trust Charles I to command it. The dispute fed the Grand Remonstrance of November 1641 and the Militia Ordinance of 1642, and it helped bring on the English Civil War in August 1642.

Key people

• Sir Phelim O’Neill (c. 1604–1653): Ulster landowner who led the rising in the north. He was captured in 1653, tried and executed in Dublin.
• Rory O’More (c. 1600 – after 1652, date of death uncertain): one of the chief organisers, who worked to bring Old English and Gaelic Irish together.
• Connor Maguire, Lord Maguire (1612–1645): arrested in Dublin on the eve of the rising and later executed at Tyburn in London.
• Owen O’Connolly: the informer whose warning saved Dublin Castle.
• Owen Roe O’Neill (c. 1585–1649): a professional soldier from Spanish service who returned in 1642 to command the Confederate army in Ulster.

Timeline

• 1609: The Plantation of Ulster begins the large-scale settlement of English and Scottish Protestants.
• 1641, 22 October: Owen O’Connolly reveals the plot; Sir Phelim O’Neill seizes Charlemont and Dungannon.
• 1641, 23 October: The planned attack on Dublin Castle fails; the rising spreads across Ulster.
• 1641, November: Killings of settlers at Portadown; the Grand Remonstrance passes the Commons in London on 22 November.
• 1641, 29 November: Irish forces defeat a government column at Julianstown.
• 1642, April: A Scottish army under Robert Monro lands at Carrickfergus.
• 1642, October: The first General Assembly of the Confederation of Kilkenny meets.
• 1649–1653: Cromwellian conquest of Ireland, followed by large-scale land confiscation.

Legacy

After the Cromwellian conquest, beginning with the Siege of Drogheda in 1649, the 1641 rising was used to justify the confiscation of most remaining Catholic-owned land. By the late 1650s the Catholic share of Irish land had fallen sharply, a transformation that shaped Irish society for two centuries.

For Irish Protestants, 1641 became a defining memory of massacre and survival. An Act of the Irish Parliament made 23 October a day of thanksgiving, observed in the Church of Ireland until 1859. For many Catholics, the rising was remembered as a desperate response to dispossession, and the later reprisals loomed larger than the original killings. Historians today try to hold both experiences in view.

Why it matters

The 1641 rebellion was the moment when the tensions created by plantation in Ireland exploded into violence. It led directly to the Confederate Wars and the Cromwellian land settlement, helped trigger civil war in Britain, and created a powerful and lasting story of grievance on both sides of Ireland’s religious divide.