Not long afterwards, however, the Irish colonel, who had many adversaries or rivals, quit the imperial service, and, making use of the liberty which he had reserved to himself, returned into Poland, where he fought against the Muscovites in the Smolensk War. He was at least in so far consistent in his choice of side, that he served against an enemy who on principle excluded mercenaries professing the faith of Rome (Herrmann, Geschichte des Russischen Reiches, iii. 54).