When the King’s army began to assemble in 1642 Sir Lewis was appointed Colonel of a regiment of foot, the rendezvous of which was to be at Nottingham on 13 August Mrs. Hutchinson, wife of the famous Parliamentary Colonel, describes some events in Nottinghamshire at this time :—

a troop of Cavaliers, under the command of Sir Lewis Dives, came to Stanton, near Owthorpe, and searched Mr. Needham’s house, who was a noted puritan in those days, and a colonel in the parliament’s service, and governor of Leicester : they found not him, for he hid himself in the gorse, and so escaped them. His house being lightly plundered, they went to Hickling, and plundered another puritan house there, and were coming to Owthorpe, of which Mr. Hutchinson having notice went away to Leicestershire; but they, though they had orders to seize Mr. Hutchinson, came not at that time because the night grew on.” On 27 August a party of royalists came out of Leicestershire and sacked the house of one Mr. Purslin, near Coventry : “Sir —— Dives” is mentioned as taking part in the affair.

The regiment was at Shrewsbury on 16 September, and later in the same month there was a skirmish outside Worcester between royalists, under Prince Rupert, and a Parliamentary force under Nathaniel Fiennes, son of Lord Say and Sele. Clarendon describes the engagement in which Sir Lewis commanded a detachment of horse :—

The Prince … espied a fair body of horse, consisting of near five hundred, marching in very good order up a lane within musket shot of him … declaring that he would charge, his brother, the lord Digby, commissary general Wilmot, sir John Byron, sir Lewis Dives, and all those officers and gentlemen whose troops were not present or ready, put themselves next the prince; the other wearied troops coming in order after them.

And in this manner the prince charged them as soon as they came out of the lane and being seconded by this handful of good men … the whole body was routed … Of the King’s party none of name was lost: commissary general Wilmot hurt with a sword in the side and Sir Lewis Dives in the shoulder and two or three officers of inferior note.