The English overlords of Ireland had used forced emigration as a way of pacifying Ireland since the start of the century, but the Cromwellian invasion gave vent to a holocaust in Ireland. Between 1641 and 1652, over 550,000 Irish were killed by the English. 300,000 were forced into indentured servitude, and the Irish population of Ireland fell from 1,466,000 to 616,000.