The "anti-Normanist" view is that the Rus' were Slavic people from south of Kiev. In support of this theory it has been pointed out that several rivers have similar names. Once example is the Ros river which is a tributary of the Dnieper river. This may have been where the Rus' took their name. The official Soviet Union history did not include the "anti-norman" viewpoint giving the reason: "The Normanist theory is politically harmful, because it denies the ability of the Slavic nations to form an independent state by their own efforts." 