Externally the Scots treated the King with all the respect due to his rank; but they allowed him no liberty whatever. On the march to Newcastle, which was made with the utmost haste—for they were always afraid of opposition from the Independent army—the King sought to ascertain how they were inclined towards him from an officer whom he trusted. As this man was telling him that he must regard himself as a prisoner, Lesley gave him a proof of the fact by peremptorily interrupting the conversation. Only Montereuil, to whom it could not be refused, was allowed to see the King occasionally; otherwise no one was admitted. The sentinels posted round his quarters were ordered to keep good watch on the windows, that letters might not be thrown out unobserved and received below. The Scots wished to separate their King from all the world, and keep him exclusively under their own influence; for their main object was to induce him actually to make the concessions which were necessary to the consolidation of Presbyterianism in Scotland and in England.

As Charles I had already declared himself willing to receive instruction in Presbyterianism, an attempt was first of all made to convince him of the truth of that system. Alexander Henderson, whom the King already liked, was immediately despatched to Newcastle, to ‘heal the prince as a good physician of the predilection which he had for the Episcopalian system.’