This antagonism reached its height in the Cromwellian era, and the men of those times stand forth upon the page of history as the exponents of the great principles of civil freedom. The strength of the Cromwellian party lay in the fact that it was composed almost entirely of the laboring and the middle classes, the bone and sinew of the land. Then for the first time in English history the world saw the plebeian pitted against the aristocrat, and the strife which ensued involved not so much the question of kingly prerogative and the 'divine right' of monarchs, as the pent-up feuds of ages--feuds arising from the most flagrant injustice and wrong on the one hand and forced submission on the other. This of itself was enough to lend to the contest a character of ferocity which well might make civilization turn pale. But even this bitterness was slight compared with that engendered by the _religious_ element of the war. The history of the world has shown no wars so cruel and bloody, no crimes so heinous, no hatred so deep seated and abiding as those produced by religious differences. Strange that it should be so! Strange that the sacred cause whose province is to develop the purest and holiest emotions of the soul, should call forth and develop the fiercest, the darkest, and most unrelenting passions of the human heart! Yet so it proved in this instance. Their fierce, fanatical enthusiasm was a powerful element of strength to the Roundheads, which was lacking to the effeminate, corrupt, and godless Cavaliers. With such an auxiliary the struggle could not be doubtful; religious fanaticism carried the day.