As the English Royalist uprisings were close to collapse, it was on the adventures of the Engager Scottish army that the interest of the war centred.
It was by no means the veteran army of the Earl of Leven, which had long been disbanded.
Hamilton's army, too, was so ill provided that as soon as England was invaded it began to plunder the countryside for the bare means of sustenance.
On 8 July the Scots, with Langdale as advanced guard, were about Carlisle, and reinforcements from Ulster were expected daily.
Lambert's horse were at Penrith, Hexham and Newcastle, too weak to fight and having only skilful leading and rapidity of movement to enable them to gain time.
Appleby Castle surrendered to the Scots on 31 July, whereat Lambert, who was still hanging on to the flank of the Scottish advance, fell back from Barnard Castle to Richmond so as to close Wensleydale against any attempt of the invaders to march on Pontefract.
On 13 August, while Cromwell was marching to join Lambert at Otley, the Scottish leaders were still disputing whether they should make for Pontefract or continue through Lancashire so as to join Lord Byron and the Cheshire Royalists.
On 14 August 1648 Cromwell and Lambert were at Skipton, on 15 August at Gisburn and on 16 August they marched down the valley of the Ribble towards Preston with full knowledge of the enemy's dispositions and full determination to attack him.
Elsewhere, however, the rebellion, which had been put down by rapidity of action rather than sheer weight of numbers, still smouldered.
There, pressed furiously in rear by Cromwell's horse and held up in front by the militia of the midlands, the remnant of the Scottish army laid down its arms on 25 August.
Various attempts were made to raise the Royalist standard in Wales and elsewhere, but Preston was the death-blow to the Royalist hopes in the Second Civil War.
Langdale called in his advanced parties, perhaps with a view to resuming the duties of advanced guard, on the night of 13 August, and collected them near Longridge.
It is not clear whether he reported Cromwell's advance, but, if he did, Hamilton ignored the report, for on 17 August Monro was half a day's march to the north, Langdale east of Preston, and the main army strung out on the road to Wigan, Major-General William Baillie with a body of foot, the rear of the column, being still in Preston.
All the restless energy of Langdale's horse was unable to dislodge Lambert from the passes or to find out what was behind that impenetrable cavalry screen. Cromwell had received the surrender of Pembroke Castle on 11 July, and had marched off, with his men unpaid, ragged and shoeless, at full speed through the Midlands.