invade Scotland. The English and Scottish parliaments then threatened to attack this army. In the midst of this, Gaelic Irish landowners in Ulster, led by Felim O'Neill and Rory O'More, planned a rebellion to take over the administration in Ireland. On 23 October 1641, the Ulster Catholics staged a rebellion. The mobilised natives turned on the British colonists, massacring about 4000 and expelling about 8,000 more. Marianne Elliott believes that "1641 destroyed the Ulster Plantation as a mixed settlement". The initial leader of the rebellion, Felim O'Neill, had actually been a beneficiary of the Plantation land grants. Most of his supporters' families had been dispossessed and were likely motivated by the desire to recover their ancestral lands. Many colonists who survived rushed to the seaports and went back to Great Britain. The massacres made a lasting impression on psyche of the Ulster Protestant population. A.T.Q. Stewart states that "The fear which it inspired survives in the Protestant subconscious as the memory of the Penal Laws or the Famine persists in the Catholic." He also believed that "Here, if anywhere, the mentality of siege was born, as the warning bonfires blazed from hilltop to hilltop, and the beating drums summoned men to the defence of castles and walled towns crowded with refugees." In the summer of 1642, the Scottish Parliament sent some 10,000 soldiers to quell the Irish rebellion. In revenge for the massacres of Scottish colonists, the army committed many atrocities against the Catholic population. Based in Carrickfergus, the Scottish army fought against the rebels until 1650, although much of the army was destroyed by the Irish forces at the Battle of Benburb in 1646. In the northwest of Ulster, the colonists around Derry and east Donegal organised the Laggan Army in self-defence. The British forces fought an inconclusive war with the Ulster Irish led by Owen Roe O'Neill. All sides committed atrocities against civilians in this war, exacerbating the population displacement begun by the Plantation. In addition to fighting the Ulster Irish, the British settlers fought each other in 1648–49 over the issues of the English Civil War. The Scottish Presbyterian army sided with the King and the Laggan Army sided with the English Parliament. In 1649–50, the New Model Army, along with some of the British colonists under Charles Coote, defeated both the Scottish forces and the Ulster Irish. As a result, the English Parliamentarians (or Cromwellians) were