He transferred to the new small Royalist army of Charles II, serving as a Life Guard until he was dismissed after becoming a Roman Catholic.
Jones volunteered to join Sir William Lockhart's Brigade which fought alongside the French army at the siege of Dunkirk and at the Battle of the Dunes on 4 June 1658.
The regiment was under the command of Lieutenant-Colonel Roger Fenwick when it attacked veteran Spanish soldiers ensconced on top of 150 feet (46 m) dune (sand-hill).
[5] Hampton Court, July 17.—His Highness [Oliver Cromwell] hath been pleased ... to confer the honor of Knighthood upon Henry Jones, Esq.
a gentleman that hath given more then ordinary proofs of high courage in several services; particularly in the late battle near Dunkirk, where, as a volunteer, he performed service on foot, along with that gallant Gentleman Lieutenant-Colonel Roger Fenwick (who sustaining the first fury of the enemy, received his death's-wound, and lies asleep in the bed of honor) in which action the said volunteer was also wounded; and afterwards mounting himself he struck in with the French horse, and among them did farther service against the enemy; whereby he stands a noble example to the young gentry of England.At the Restoration, he found his way into a lieutenant's commission in Lord Hawley's troop in the Royal Horse Guards, probably through the patronage and influence of George Monck and Sir William Lockhart.
Appreciative of the loyalty they had shown, he made arrangements for these officers to enter service of the French Army, in Sir George Hamilton's regiment.
[13] Jones was one of those who left England for service abroad - reportedly, he converted to Roman Catholicism some time before the act of Parliament.