No, Cossacks are descendants of feudal lords and slaves in the ancient Russian era, and their ethnic composition is complex. Later, some slaves and poor peasants fled to the Don River valley and gradually formed a group to make a living by looting their homes. Look at Liangshan heroes in the water margin. Cossack is a general term for the kind of refugees who fled. Cossacks are not a nation, but they are famous for their bravery and good fighting. Cossacks are not a nation, let alone a Slavic nation. . . Most Cossacks are descendants of Slavs or Mongolian Tatars. . . With the advent of the era of peace and the mechanization of modern warfare, Cossacks, mainly cavalry, were killed or returned to normal society in World War I and the Soviet-Russian revolution, and almost 3 million people were killed. . . Cossack is a bandit in Russian culture, and his role in Russian history is similar to that of the East India Company, that is, mercenaries and colonists.