When he rose to command an army, Cromwell’s management of it in battle was marked by the same characteristics as his handling of his division of cavalry. In the early battles of the Civil War there was a strong family likeness: there was an absence of any generalship on either side. The general-in-chief exhibited his skill by his method of drawing up his army and his choice of a position; but when the battle began the army seemed to slip from his control. Each commander of a division acted independently; there was little co-operation between the different parts of the army; there was no sign of a directing brain. Cromwell, on the other hand, directed the movements of his army with the same purposeful energy with which he controlled his troopers. Its different divisions had each their definite task assigned to them, and their movements were so combined that each played its part in carrying out the general plan. The best example of Cromwell’s tactical skill is the battle of Dunbar. There, though far inferior in numbers, Cromwell held in check half the enemy’s army with his artillery and a fraction of his forces, while he attacked with all his strength the key of the enemy’s position, and decided the fate of the day by bringing a strong reserve into action at the crisis of the battle. Whenever the victory was gained it was utilised to the utmost. At Dunbar the Scots lost thirteen thousand men out of twenty-two thousand; after Preston less than a third of Hamilton’s army succeeded in effecting their return to Scotland: after Worcester, not one troop or one company made good its retreat.
Cromwell’s strategy, compared with that of contemporary generals, was remarkable for boldness and vigour. It reflected the energy of his character, but it was originally dictated by political as well as military considerations. “Without the speedy, vigorous, and effectual prosecution of the war,” he declared in 1644, the nation would force Parliament to make peace on any terms. “Lingering proceedings, like those of soldiers beyond seas to spin out a war,” must be abandoned, or the cause of Puritanism would be lost. Therefore, instead of imitating the cautious defensive system popular with professional soldiers, he adopted a system which promised more decisive results. “Cromwell,” says a military critic,. “was the first great exponent of the modern method of war. His was the strategy of Napoleon and Von Moltke, the strategy which, neglecting fortresses and the means of artificial defence as of secondary importance, strikes first at the army in the field.”
In his Preston campaign Cromwell had to deal with an invading army more than twice the strength of his own, which ventured because of that superiority to advance without sufficient scouting and without sufficient concentration. He might have thrown himself across Hamilton’s path and sought to drive him back; he chose instead to fall upon the flank of the Scots, and thrust his compact little force between them and Scotland. Thus he separated the different divisions of Hamilton’s army, drove Hamilton with each blow farther from his supports, and inflicted on him a crushing defeat instead of a mere repulse. In 1650 and 1651, Cromwell had a much harder task given him. He had to invade a country which presented many natural difficulties, and which was defended by an army larger than his own under the command of a man who was a master of defensive strategy. All his efforts to make Leslie fight a pitched battle in the open field completely failed until one mistake gave him the opportunity which he seized with such promptitude at Dunbar. In the campaign of 1651, Cromwell found himself brought to a standstill once more by Leslie’s Fabian tactics. As Leslie gave him no opportunity he had to make one, and with wise audacity left the way to England open in order to tempt the Scots into the invasion which proved their destruction.
In his Irish campaigns Cromwell had an entirely different problem to solve. The opposing armies were too weak to face him in the field and too nimble to be brought to bay. The strength of the enemy consisted in the natural and artificial obstacles with which the country abounded: fortified cities commanding points of strategic value; mountains and bogs facilitating guerrilla warfare; an unhealthy climate, a hostile people, a country so wasted that the invader must draw most of his supplies from England. Under these conditions the war was a war of sieges, forays, and laborious marches, but there were no great battles. Cromwell combined the operations of his army and his fleet so as to utilise to the full England’s command of the seas. He attacked the seaports first, and after mastering them secured the strong places which would give him the control of the rivers, thus gradually tightening his grasp on the country till its complete subjugation became only a matter of time.
Opinions may differ as to the comparative merits of these different campaigns. What remains clear is that Cromwell could adapt his strategy with unfailing success to the conditions of the theatre in which he waged war and to the character of the antagonists he had to meet. His military genius was equal to every duty which fate imposed upon him.
Experts alone can determine Cromwell’s precise place amongst great generals. Cromwell himself would have held it the highest honour to be classed with Gustavus Adolphus either as soldier or statesman. Each was the organiser of the army he led to victory, each an innovator in war—Gustavus in tactics, Cromwell in strategy. Gustavus was the champion of European Protestantism as Oliver wished to be, and each while fighting for his creed contrived to further also the material interests of his country. But whatever similarity existed between their aims the position of an hereditary monarch and an usurper are too different for the parallel to be a complete one. On the other hand, the familiar comparison of Cromwell with Napoleon is justified rather by the resemblance between their careers than by any likeness between their characters. Each was the child of a revolution, brought by military success to the front rank, and raised by his own act to the highest. Each, after domestic convulsions, laboured to rebuild the fabric of civil government, and to found the State on a new basis. But the revolutions which raised them to power were of a different nature and demanded different qualities in the two rulers.
Cromwell’s character has been the subject of controversies which have hardly yet died away. Most contemporaries judged him with great severity. To Royalists he seemed simply, as Clarendon said, “a brave, bad man.” Yet while Clarendon condemned he could not refrain from admiration, for though the usurper “had all the wickedness against which damnation is pronounced, and for which hell fire is prepared, so he had some virtues which have caused the memory of some men in all ages to be celebrated.” Though he was a tyrant he was “not a man of blood,” and he possessed not only “a wonderful understanding in the natures and humours of men,” but also “a great spirit, an admirable circumspection and sagacity, and a most magnanimous resolution.”
The Republicans regarded the Protector as a self-seeking apostate. “In all his changes,” said Ludlow, “he designed nothing but to advance himself.” He sacrificed the public cause “to the idol of his own ambition.” All was going well with the State, a political millennium was at hand, “and the nation likely to attain in a short time that measure of happiness which human things are capable of, when by the ambition of one man the hopes and expectations of all good men were disappointed.”
Baxter, a Presbyterian, though as convinced an opponent of the Protector as Ludlow, was a more generous critic. According to him, Cromwell was a good man who fell before a great temptation. He
“meant honestly in the main, and was pious and conscionable in the main course of his life, till prosperity and success corrupted him. Then his general religious zeal gave way to ambition, which increased as successes increased. When his successes had broken down all considerable opposition then was he in face of his strongest temptations, which conquered him as he had conquered others.”