While trying and executing Montrose for loyalty to the king, the Scots were themselves negotiating with Charles, commissioners having come over to Breda, where he was living, for the purpose.  They insisted upon his swearing to be faithful to the Covenant, to his submitting himself to the advice of the Parliament and Church, and to his promising never to permit the exercise of the Catholic religion in any part of his dominions.  Charles agreed to everything demanded of him, having all the time no intention whatever of keeping his promises.  While he was swearing to observe everything the Scots asked of him, he was writing to Ormonde to tell him that he was to mind nothing he heard as to his agreement with the Scots, for that he would do all the Irish required.  Charles, indeed, although but a young man of twenty, was as full of duplicity and faithlessness as his father, without possessing any of the virtues of that unfortunate king, and the older and wiser men among his followers were alienated by his dissolute conduct, and by the manner in which he gave himself up to the reckless counsels of men like Buckingham and Wilmot.

Harry heard with deep regret the many stories current of the evil life and ways of the young king.  Had it not been for the deadly hatred which he felt to Cromwell and the Puritans for the murder of Sir Arthur Ashton, and the rest of the garrison and people of Drogheda, in cold blood, he would have retired altogether from the strife, and would have entered one of the continental armies, in which many Royalist refugees had already taken service.  He determined, however, that he would join in this one expedition, and that if it failed he would take no further part in civil wars in England, but wait for the time, however distant, when, as he doubted not, the people of England would tire of the hard rule of the men of the army and conventicle, and would, with open arms, welcome the return of their sovereign.

Early in June the king sailed for Scotland, accompanied by the regiment which Harry had raised, and a few hundred other troops.  He landed there on the 16th.  The English Parliament at once appointed Cromwell captain-general and commander-in-chief of all the forces raised and to be raised within the commonwealth of England.  A few days later he left London, and on the 23d of June entered Scotland with sixteen thousand men.  King Charles, to whom Harry had been presented by Prince Rupert as one of his father’s most gallant and faithful soldiers, received him at first with great cordiality.  As soon as he found, however, that this young colonel was in no way inclined to join in his dissipations, that his face was stern and set when light talk or sneers against religion were uttered by the king’s companions, Charles grew cold to him, and Harry was glad to be relieved from all personal attendance upon him, and to devote himself solely to his military duties.  Upon landing in Scotland, Harry, with his regiment, was encamped in the valley between Edinburgh