Eastern Europe is a historical concept, Niederhauser asserts, and as such is subject to the movement of history that often takes place under geographical conditions. A History of Eastern Europe Since the Middle Ages surveys the first five hundred years of Eastern European history, focusing on structural elements in the early period such as the lack of organized states or the existence of nomadic states. The book examines the disappearance, assimilation, and recurrence of ethnic cultures over time and how the intermixing of cultures influenced the formation of modern states.