This phase of the war was by far the most costly in terms of civilian loss of life. The combination of warfare, famine and plague caused a huge mortality among the Irish population. William Petty estimated (in the 1655-56 Down Survey ) that the death toll of the wars in Ireland since 1641 was over 618,000 people, or about 40% of the country's pre-war population. Of these, he estimated that over 400,000 were Catholics, 167,000 killed directly by war or famine, and the remainder by war-related disease.  Modern estimates put the toll at closer to 20%. 
Cromwell is among the most controversial figures in the background of the British Isles, considered a regicidal oppressor by chroniclers such as David Sharp, an army totalitarian by Winston Churchill, but a hero of freedom by John Milton, Thomas Carlyle, as well as Samuel Rawson Gardiner, and also a class revolutionary by Leon Trotsky. In a 2002 BBC poll in Britain, Cromwell was picked as one of the 10 best Britons of perpetuity. Nonetheless, his measures against Catholics in Scotland and also Ireland have actually been qualified as genocidal or near-genocidal, as well as in Ireland his life and actions are still highly criticised.