A lot of the Scots wanted to put Charles II (pervert and tyrant) onto the throne. Cromwell put a stop to that with force. (the Scots got their wish after Cromwell's death--and Charles II demanded blood for payment, hence the "killing times.") Here are some good things said about Cromwell:
He sailed right into the harbor, adn though the shore was planted with heavy guns, he burnt nine of the Turkish vessels, and brought the tyrant to reason. But he did not confine himself to this mission: he spread the terror of the English name over all of Italy, even to Rome itself (211).
Cromwell himself reflects on his army,
I raised such men as had the fear of God before them, as made some conscience of what they did; and from that day forward, I must say to you, they were never beaten, and wherever they engaged the enemy, they beat continually (240-241).
D'Aubigne concludes:
Without Cromwell, humanly speaking, liberty would have been lost not only to England, but to Europe (278).