In Lancashire the way was now open for the siege of the last royalist strongholds. Only two places still held out to the King, Lathom House and Greenhalgh Castle, and of these the former was much the more important.
The Earl of Derby was still in the Isle of Man, but Lathom under the able direction of the Countess of Derby, assisted by such Lancashire royalists as still remained in the county, had been gradually prepared for resistance. It being almost the only place of refuge left, many of the militant royalists had gathered there. The House had been summoned as far back as May, 1643, after the capture of Warrington; but nothing had been done towards reducing it. The royalists had been, however, practically confined to the Park at Lathom, and Rigby sent what troops he could spare to harass them at intervals. The garrison on their part plundered all they could. Early in February, 1644, the royalists had the better of a skirmish with some Parliamentarian horse under Captain Hindley; and when the danger in Cheshire was over the troops from Cheshire were at liberty to begin the reduction of Lathom.
The first siege of Lathom House is quite the most picturesque incident of the Lancashire war. More has been written about it, and it is probably better known than any other event. This has rather served to disguise the fact that the siege was not very important from a military point of view. There was no great issue depending upon its capture as in the case of that of Manchester in October, 1642, or of Warrington in April, 1643; its resistance for a few months more or less did not affect the general position. It was a centre of hostile influence, but its garrison was bound to be only on the defensive and could never hope to be strong enough to make Lathom the starting point for a re-conquest of Lancashire for the King. Thus the defence was in the nature of a forlorn hope, and derived from this greater interest; when it is added that the defence was directed by a woman after the Earl of Derby and lesser royalist leaders had been driven out of the county, it easily became 'ever memorable' to the royalists. The attempt to save a splendid and historic mansion from the destruction which afterwards unhappily overtook it makes a further appeal to the imagination; and that the attempt was successful owing to the appearance on the scene of the chivalrous figure of Prince Rupert, supplies the last touch of sentimental interest.