Dnieper Cossacks

Military History of Ukraine
Kievan Rus' Druzhyna (862–1240)
Kingdom of Galicia–Volhynia Voyi
Polish–Lithuanian Commonwealth Registered Cossacks Zaporozhian Cossacks (1492–1648)
Zaporizhian Host Zaporozhian Cossacks (1648–1775)
Austria-Hungary Legion of Sich Riflemen (1914–1918)
Ukrainian People's Republic Ukrainian People's Army (1917–21) Sich Riflemen (1917–21) Ukrainian Galician Army (1918–19)
Free Territory Revolutionary Insurrectionary Army (1918–1921)
Carpatho-Ukraine Carpathian Sich (1938-39)
Ukrainian National Government UPRA (1941–1944) Ukrainian Insurgent Army (1941–1955)
Ukrainian SSR Red Cossacks Ukrainian Soviet Army () (1918–19) none (1919–1991), part of the Soviet Armed Forces
Ukraine Armed Forces (1992–Present) This box:

The Zaporozhian Cossacks, Zaporozhian Cossack Army, Zaporozhian Host (Ukrainian: Військо Запорізьке, Russian: Войско Запорожское) or simply Zaporozhians (Ukrainian: Запорожці Zaporozhtsi, Russian: Запорожцы Zaporozhtsy, Polish: Kozacy zaporoscy, Czech: Záporožští kozáci) were Cossacks who lived beyond the rapids of the Dnieper River, the land also known under the historical term Wild Fields in today's Central Ukraine. Today much of its territory is flooded by the waters of Kakhovka Reservoir.

The Zaporizhian Sich grew rapidly in the 15th century from serfs fleeing the more controlled parts of the Polish–Lithuanian Commonwealth. It became established as a well-respected political entity with a parliamentary system of government. During the course of the 16th, 17th and well into the 18th century, the Zaporozhian Cossacks became a strong political and military force that challenged the authority of the Polish–Lithuanian Commonwealth, the Tsardom of Russia, and the Crimean Khanate.

The Host went through a series of conflicts and alliances involving the three powers, including supporting an uprising in the 18th century. Their leader signed a treaty with the Russians. This group was forcibly disbanded in the late 18th century by the Russian Empire, with most of the population relocated to the Kuban region in the South edge of the Russian Empire. The Cossacks served a valuable role of conquering the Caucasian tribes and in return enjoyed considerable freedom granted by the Tsars.

...
Wikipedia