Such was the picture which framed itself in Cromwell's mind in the contemplation of the troubles of 1641. It was no long by-past history that he ignored—though the race against which his sword was drawn was one singularly retentive of the tradition of days long-ago. It was the occurrences which had passed in his own life-time which he misinterpreted. The Irish peoples and tribes, it seemed, had had no grievances of which to complain. They had never, forsooth, been ousted from their land by the chicanery of English lawyers and English statesmen. As for their religion, it was hardly to be regarded as a religion at all. Favour enough was shown to them if they were allowed to bury their creed in their hearts, though they were deprived of those consolations on which those who held their faith were far more dependent than the adherents of other Churches. That Cromwell believed every word he said is not to be doubted. This representation of Irish problems and of Irish facts was no creation of his own mind. It was the common—probably the universal belief of Englishmen of his own day.

Nor was Cromwell any more original in propounding remedies. "We are come," he continued, "to take an account of the innocent blood that hath been shed, and to endeavour to bring them to account—by the blessing of Almighty God, in whom alone is our hope and strength—who by appearing in arms seek to justify the same. We come to break the power of a company of lawless rebels who, having cast off the authority of England, live as enemies to human society, whose principles—the world hath experience of—are to destroy and subjugate all men not complying with them. We come—by the assistance of God—to hold forth and maintain the lustre and glory of English liberty, in a nation where we have an undoubted right to do it, whereas the people of Ireland—if they listen not to such seducers as you are—may equally participate in all benefits to use liberty and fortune equally with Englishmen, if they keep out of arms." Irishmen, in short, were to be what Englishmen were, or to bear the penalty. It was the old remedy of the Elizabethans and of Strafford. It is not so much the victorious sword that alienates as the contempt of the conqueror for all that the conquered are in themselves or for all that they hold dear. Yet it must be acknowledged that in whatever proportion the guilt of past errors may be divisible between English and Irish, no English government could endure longer to face that danger of invasion from the side of Ireland, which had so constantly threatened England since first her civil broils began. Under these circumstances, an English conquest of Ireland was inevitable as soon as it was undertaken by a disciplined army. Irishmen were too deeply riven asunder by diversities of race and institutions to unite in common resistance; and even if these difficulties could be removed, there was no common leader who commanded universal devotion. Conquered—Ireland was bound to be, but it was unfortunate for both peoples that she was conquered at a time when the religious and political ideas of Englishmen were, more than ever before or since, the antithesis of those of Irishmen. It was when a Puritan Government took in hand what they hoped to be the regeneration of Ireland that the real difficulties of the task would be made manifest.

No such gulf was open between England and Scotland, yet the apprehension of fresh troubles approaching from Scotland caused the Government at Westminster to recall Cromwell in May 1650. For some time a negotiation had been carried on at Breda between the exiled Charles II. and a body of commissioners who had been sent by the extreme Presbyterians now dominant in Edinburgh, with the object of persuading the young King to accept their assistance to regain his other kingdoms on conditions which could not fail to be most repulsive to him. He was to disallow the treaty concluded by Ormond, by which the Irish were exempted from the penal laws, though in that treaty lay his sole hope of resisting Cromwell in that country; he was to establish Presbyterianism both in England and Ireland without a shred of toleration either for the sects or for that Church of which he was himself a member, and he was to sign the two Covenants, marking his own adhesion to the Scottish form of religion. Against these terms Charles long struggled, but on May 1 he signed the draft of an agreement assenting to them, which was sent to Scotland for approval, accompanied by a demand on his part for their modification. Before an answer was received, Charles heard that his most gallant champion, Montrose, had been defeated and hanged as a traitor. A day or two later, on June 1, he was informed that his request for the modification of the Scottish terms had been rejected at Edinburgh. On the 2nd Charles embarked for Scotland without signing anything, and it was only on June 11, off Heligoland, that he affixed his name to the treaty, and only on the 23rd, off Speymouth, that he swore to the Covenants, as the treaty required him to do. There can be little doubt that he intended to cast off the bondage as soon as an opportunity arrived. It is doubtful which was the greater, the ignorance of the Scottish Government in supposing that their conditions could be imposed on England, or their folly in imagining that Charles would be bound by his oath to become their accomplice. Of this Government Argyle was still the leading personality, but that shrewd statesman only held his own by submitting to the crowd of fanatics, clerical and lay, whom he had once hoped to control, and who now made themselves his masters. Secret communications had long been passing between Charles and his English supporters. They were expected to rise in support of the Scots, but as to the engagement to establish Presbyterianism, it 'was by most refused, and resolved to be broken by those who took it'.

Under these circumstances, Cromwell's return had been ardently expected by all who had attached themselves to the existing Government. Whilst he was still absent, Parliament had secured to him the use of the Cockpit—a house opposite Whitehall—and also of St. James's House and Spring Gardens; and had afterwards voted to him an additional grant of lands bringing in £2,500 a year. On June 1 he had a magnificent reception as he crossed Hounslow Heath, and on the 4th received the thanks of Parliament for his services. The first question mooted was on whom should be bestowed the command of the army destined for the north. As long as it was expected that the troops were to act on the defensive, Fairfax was ready to go with Cromwell serving under him, as in old days, as his Lieutenant-General.

On June 20, when it was resolved, doubtless at Cromwell's suggestion, that the English army should invade Scotland to anticipate an attack which was regarded as inevitable, Fairfax's hesitations began, and after a brief delay he offered to resign his commission. Cromwell did his best to combat his arguments, which proceeded rather from a general feeling of distrust of the tendency of the Commonwealth Government than from any distinct resolve to separate himself from it. Cromwell's persuasions were of no avail, and on June 26 he received the appointment of Lord General, which Fairfax was now permitted to resign. Cromwell's mind was set on something more than military success. In a conversation with Ludlow who was about to leave for Ireland, he discoursed for an hour on the 110th Psalm. "He looked," he said, "on the design of the Lord in this day to be the freeing of the people from every burden." Especially he found hard words to fling at the lawyers—those sons of Zeruiah who had hitherto stood in the way of the simplifying of the law in favour of poorer litigants.

On June 28 Cromwell set out for his command. At Berwick on July 19 he found himself at the head of 16,000 men, whilst the Scottish army, under the command of David Leslie, numbered 26,000. For the first time in his life Cromwell was opposed to a general who was a capable strategist. The Scottish army, moreover, had the advantage of position. Occupying Edinburgh Castle and the fortified city sloping eastwards beneath it, Leslie had thrown up intrenchments from the foot of the Canongate to Leith, to bar the way to any army threatening to cut off the city from its port. Cromwell, having failed to carry this line, retreated to Musselburgh to prepare for his next step.

Though the Scots had the advantage of military position, their army had none of the coherence of the English. The clergy, under whose influence it had been gathered, had a shrewd suspicion that Charles was not whole-hearted in his devotion to the Kirk. They were afraid of his influence on the soldiers, and when he made his appearance at Leith they compelled him to withdraw. His expulsion was followed by a purge of the army, and in three days no fewer than 80 officers and 3,000 soldiers were dismissed as not coming up to the proper spiritual or moral standard. To the clergy Cromwell's appeal was directed in vain. "I beseech you," he wrote to them, "in the bowels of Christ, think it possible you may be mistaken." It was the very last thing they were prepared to do. To them sectarianism was an evil to be combated at all hazards, and Cromwell's entreaties to join him in brotherly union met with no response. Yet amongst the stricter Presbyterian laity there were some—such as Strachan and Ker—who felt uncomfortable at being told that they were fighting for a malignant King. Cromwell having posted himself, on August 13, on Braid Hill, to the south of Edinburgh, committed one of the greatest faults of which a general is capable. His eagerness to win over those whom—in spite of their contumelious rejection of his claim—he persisted in regarding as his brothers in religion, led him to subordinate war to diplomacy. For the first time in his military career he was hesitating and tentative, prone to delay action, and above all inspired by the hope that action might be avoided. Even if he had acted more promptly it is possible that he might have failed against so wary an antagonist as Leslie. His plan, probably the best under the circumstances, was to march on Queensferry, in order to cut the communications of the Scottish army with its base of supplies in Fife, communications which could not be maintained lower down the Firth where the English fleet was master of the sea. Leslie held the inner line, and when at last, on August 27, Cromwell advanced towards Queensferry, he found Leslie across his path, posted behind a morass. He could but turn back once more to Musselburgh, after which, giving up the game he had been playing for some weeks, he found himself, on September 1, at Dunbar. Leslie followed, taking care to avoid a battle and drawing up his army on Doon Hill, whose steep slopes looked down on the flatter ground on which Cromwell's forces lay. Blocking the route to England by occupying the defile at Cockburnspath, Leslie had but to remain where he was to force Cromwell—now commanding less than half his former numbers—either to surrender or to ship the best part of his force for England—the fleet which accompanied him not affording space for the accommodation of his whole army. "The enemy," wrote Cromwell, "lieth so upon the hills that we know not how to come that way without difficulty, and our lying here daily consumeth our men who fall sick beyond imagination." There could be little doubt that even if the army secured its retreat to its own country, its failure to defeat the Scots would be followed by a general rising of the Cavaliers in England.

Humanly speaking, the prospect was a dark one, and Cromwell could but console himself with his trust in divine assistance. "All," he wrote, "shall work for good; our spirits are comfortable, praised be the Lord, though our present condition be as it is, and indeed we have much hope in the Lord, of Whose mercy we have had large experience." With him faith in Divine protection was consistent with the adoption of every military measure by which an adversary's mistakes could be turned to his own advantage. It was otherwise with the clergy and their adherents, who exercised so much influence on the Doon Hill. There had been fresh purging of the Scottish army, and soldiers had again been dismissed—not for any lack of military efficiency, but because their views of the Covenant were insufficiently exalted. It is said that the men who were thus weakening their own fighting power grew impatient with Leslie for not crushing the enemy by an immediate onslaught. Other causes may have combined to make the postponement of a conflict almost impossible. There was no water on the Doon Hill, and provisions for 23,000 men must have been hard to come by in that bleak region. At all events, on the 2nd the Scots began to move down the Hill. The struggle was to be transformed from a competition in strategy to a competition in tactics, and Cromwell, sure of mastery in that field, was rejoiced at the sight which met his eyes. In the early morning of the 3rd a plan of action brilliantly conceived was skilfully carried into execution; and the Scots, after a brave resistance, broke and fled. As the sun rose out of the sea, Cromwell, with the joyful exclamation on his lips: "Let God arise, let His enemies be scattered," pushed his victorious cavalry in pursuit. Before they drew rein, 3,000 of the enemy had been slain, and 10,000 captured together with the whole of the artillery. Never again did a Scottish army take the field to impose its religion upon a recalcitrant England.

"Surely," wrote Cromwell, after the battle had been won, "it's probable the Kirk has done their do. I believe their King will set up upon his own score now, wherein he will find many friends." Charles himself seems to have taken the same view of the situation if it be true that, on receiving the news from Dunbar, he gave thanks to God 'that he was so fairly rid of his enemies'. At all events the key to the history of the next twelve months in Scotland is the attempt to convert a clerical into a national resistance. To Cromwell, an attempt to force England into political conformity with Scotland was as much to be resisted as an attempt to impose on her the Scottish religion. It was the despotic tendencies, not the fervour of that religion, that he disliked. The association of the laity with the clergy in the government of the Church was insufficient for him. His ideal community was one in which every layman was capable of performing spiritual functions. He would not listen to the objection of a colonel who complained that one of his officers 'was a better preacher than fighter'. "Truly," he replied, "I think that he that prays and preaches best, will fight best. I know nothing will give like courage as the knowledge of God in Christ will, and I bless God to see any in this army able and willing to impart the knowledge they have, for the good of others; and I expect it be encouraged by all the chief officers in this army especially; and I hope you will do so. I pray receive Captain Empson lovingly; I dare assure you he is a good man and a good officer. I would we had no worse."

Unluckily there was no response amongst the Scottish laymen to such an appeal as this. They were satisfied—if religiously inclined—with the part assigned to them on Kirk Sessions or Presbyteries, and preferred to take their sermons from an ordained minister. Even those Presbyterians who distrusted a malignant King held aloof from the sectarian Englishman.