The Cossacks

During the Napoleonic Wars Russia could call upon large numbers of light irregular cavalry, the Cossacks. These troops were descendants of outlaws who had settled in southern Russia and were tribal, being commanded by their tribal chiefs or atamans. They had little effect on organised disciplined troops but they were highly valued as scouts, raiders and skirmishers and harried the French Grande Armee mercilessly in 1812. They were organised by area into sotnias or squadrons and rode hardy steppe ponies. Each man had a spare pony, much like the Mongols before them. They loved weapons and normally carried various including firearms and lances as well as a knout or whip with an iron weighted end. Although some Cossack regiments had uniforms, most Cossacks outfitted themselves in their own somewhat tribal manner. In battle as already mentioned their performance against steady troops was less than impressive but they were skilled scouts and their large numbers (77,000 were listed in the Russian Army in 1795) and barbarous war crys often struck fear into their enemies. They were robbers and looters and were often seen as filthy drunks and some of the Asiatic tribes were very primitive by the time of Napoleonic wars, with the Bashkirs and Kalmucks being little more than medieval cavalry carrying only bows and arrows and gaining the nickname 'cupids' from the French.

http://www.historyofwar.org/articles/weapons_cossacks_napoleonic.html