The Cromwellian conquest of Ireland refers to the re-conquest of Ireland by the forces of the English Parliament, led by Oliver Cromwell during the Wars of the Three Kingdoms.

Cromwell landed in Ireland with his New Model Army on behalf of the English Parliament in 1649.

Since the Irish Rebellion of 1641, Ireland has been mainly under the control of the Irish Confederate Catholics, who in 1649, signs an alliance with the English Royalist party, which had been defeated in the English Civil War.

Cromwell's forces defeat the Confederate and Royalist coalition in Ireland and occupy the country - bringing to an end the Irish Confederate Wars.

He passes a very harsh series of Penal laws against Roman Catholics and confiscates almost all of their land.

The Parliamentarian reconquest of Ireland is extremely brutal, and it has been alleged that many of the army's actions during the reconquest would today be called war crimes or even genocide.

Cromwell is still a hated figure in Ireland.

It has recently been argued by one historian that many of the actions taken by Cromwell were within the then-accepted rules of war, or were exaggerated or distorted by later propagandists, but these claims are not accepted by most historians.

The Parliamentarian campaign, which Cromwell largely heads, is estimated to have resulted in the death or exile of about 15-20% of the Irish population.