A summary of Cromwell’s character by a royalist
(Earl of Clarendon, Edward Hyde: The History of the Great Rebellion, Vol. III, part 1, p.432, p.509. Published at Clarendon Printing House, 1767-1786)
There cannot be a greater demonstration of the general prejudice and dislike in the whole kingdom towards Cromwell, and his government, than the many plans and plots against him, which were passed on to so many men. Notable persons could go to London, and remain there, without any discovery being made that might allow Cromwell to have them arrested. ……
To sum up his character, Cromwell was not so much a man of blood as to follow Machiavelli’s method. (This says it is absolutely necessary, after a total change of government, to cut off all the heads of those who are friends of the old government, and destroy their families.) It was confidently reported that in the Council it was more than once suggested, “that there might be a general killing of all the royal party”, as the only way to keep the government in power. But Cromwell would never agree to it, maybe because he had little respect for his enemies [not seeing them as enough of a threat to kill them]. In a word, he was guilty of many crimes for which he will be damned and for which hell-fire is prepared. He also had some good qualities, which have caused the memory of some men in all ages to be celebrated. He will be looked upon in future as a brave wicked man.