Gibbon was not alone in his fascination for the Roman Empire, and in the following generation Napoleon Bonaparte expressed his interest rather more practically by attempting to effectively refound it with himself as the new emperor. So it is quite fitting that in one his first battles as emperor, at Eylau, he should find himself up against Cossack horsemen armed with bows and arrows. They probably looked much like the Huns, also steppe nomads, who had played such a big role in the destruction of the empire that he was trying to revive.
It would be poetic if they had played a major role in his defeat, but history doesn’t work like that. They were only deployed by the Russians in desperation to cover their retreat. Armed with muskets, the French were able to cope with them with ease, contempt even. It was a bit of a sad end of a tradition going back many centuries of mounted tribesmen inspiring fear and panic in their victims.