From Scott's "Woodstock":
At length Cromwell died, his son resigned the government, and the various charges which followed induced Everard, as well as many others, to adopt more active measures in the king's behalf...After this, although the estate was terribly unsettled, yet no card seemed to turn up favorable to the royal cause, until the movement of General Monk from Scotland.
George Monck (or Monk), who died on January 3, 1670, is notable for having maneuvered politically through several regimes. One constant in his life was his military success. Monck fought against the Scots (1639-1640) and Irish (1641) under Charles I, again against the Irish under Cromwell, and at Cromwell's side against the Scots at the Battle of Dunbar (1650). Charles II appealed to Monck while he was in Cromwell's employ, but Monck was too close to the Protector to switch sides at this time. After Cromwell's death, Charles again approached Monck, who now saw an advantage in supporting Charles and the ultimate Restoration. Charles raised Monck to Duke of Albemarle in gratitude for his support, and gave him the Province of Carolina in America.