[Footnote 1:  Ludlow, 599-600; Whitlocke, IV. 330; Godwin, IV. 502-503.]

The Royalist project and its ramifications were really very formidable.  A Spanish Army of about 8000 men, with Charles II. and his refugees among them, was gathered about Bruges, Brussels, and Ostend, with vessels of transport provided; and the burst of a great Royalist Insurrection at home, in Sussex, London, and elsewhere, was to coincide with the invasion from abroad.  The Duke of Ormond himself had come to London in disguise, to observe matters and make preparations.  He was in London for three weeks, living in the house of a Roman Catholic surgeon in Drury Lane, till Cromwell, who knew the fact, generously sent Lord Broghill to him with a hint to be gone.  This was early in March, some days after a proclamation “commanding all Papists and other persons who have been of the late King’s party or his son’s to depart out of the cities of London and Westminster,” and another proclamation forbidding such persons living in the country to stir more than five miles from their fixed places of abode.  On the 12th of that month the Lord Mayor, Aldermen, and Common Council of the City of London met his Highness and the Army-officers by appointment at Whitehall, where his Highness explained to them at length the nature of the crisis, informed them particularly of the strength of the Flanders army of invasion, Ormond’s visit, &c., and solemnly committed to them the safety of the City.  The response of the City authorities was extremely loyal.[1]

[Footnote 1:  Godwin, IV. 507-508; Carlyle, III. 353-354; Merc.  Pol., of March 11-18, 1657-8, quoted in Cromwelliana, pp. 170-171.  The Proclamation ordering Papists and other Royalists out of London and Westminster, and that ordering such persons in the country to keep near home, are both dated Feb. 25, 1657-8.  There are copies at the end of one of the volumes of the Council’s minutes.]

On the principle that the country could not afford for ever this periodical trouble of a Royalist Conspiracy, and that some examples of severity might make the present upheaving the last of the kind, Cromwell had resolved on a few such examples.  His information, through Thurloe and otherwise, was unerring.  He knew, and had known for some time, who were the members of the so-called “Sealed Knot,” i.e. that secret association of select Royalists resident in England who were in closest correspondence with Hyde and the other Councillors of Charles abroad, and were chiefly trusted by them for the management of the cause at home, Indeed, Sir Richard Willis, one of the chiefs of the “Sealed Knot,” had for some time been in understanding with Cromwell, pledged to him by a peculiar compact, and revealing to him all that passed among the Royalists.  Hence, before the end of April, some of the members of the “Sealed Knot,” and a number of leading Royalists besides, had been lodged in the Tower.