Rus' was a historical region and people that emerged in Eastern Europe during the early Middle Ages. It is often associated with the formation of the first East Slavic state, known as Kievan Rus', which was established around the 9th century. The term "Rus'" is believed to have originated from the Norse word for "rowers" or "seafarers," referring to the Viking traders and warriors who played a significant role in the region's development. The Kievan Rus' was a federation of Slavic tribes under the rule of the Varangians, particularly the Rurik dynasty. It became a major cultural and political center, influencing the development of modern Russia, Ukraine, and Belarus. The adoption of Christianity in 988 further solidified its cultural identity and connections with the Byzantine Empire.