Rusʹ Khaganate (, Russkiy kaganat, , Ruśkyj kahanat), or kaganate of Rus is a name applied by some modern historians to a polity postulated to have existed during a poorly documented period in the history of Eastern Europe between 830 and the 890s. The fact that a few sparse contemporaneous sources appear to refer to the leader or leaders of Rus' people at this time with the word chacanus, which might be derived from the title of khagan as used by groupings of Asiatic nomads, has led some scholars to suggest that his political organisation can be called a "k(h)aganate". Other scholars have disputed this, as it would have been unlikely for an organisation of Germanic immigrants from the north to adopt such a foreign title. Some historians have criticised the concept of a Rus' Khaganate, calling it a "historiographical phantom", and said that the society of 9th-century Rusʹ cannot be characterised as a state. Still other scholars identify these early mentions of a Rus' political entity headed by a chacanus with the Kievan Rus' state commonly attested in later sources, whose princes such as Volodimir I (Vladimir/Volodymyr "the Great", ) Yaroslav the Wise ("Georgij", ), and perhaps Sviatoslav II of Kiev () and Oleg I of Chernigov () were still occasionally identified as kagans in Old East Slavic literature until the late 12th century. Mentions in documents Overview The word khagan for a leader of some groups of Rus' people is mentioned in several historical sources. According to Constantin Zuckerman (2000), these sources are divided into two chronological groups: three or four Latin and Arabic sources from 839 to 880 (which he labelled "1a, 1b, 1c"), while three Old East Slavic sources (labelled "2a, 2b, 2c") date from 200 years later in the 11th and 12th centuries, and are "fundamentally different". The Perso-Arabic (Islamic) sources mentioning a khāqān rus or Khāqān-i Rus all appear to follow a single common chain of tradition tracing back to the "Anonymous Note". (1a) The Latin Annales Bertiniani or "Annals of St. Bertin" (this part written by Prudentius of Troyes, who died in 861) mention certain men called Rhos, whose king (rex) they called chacanus or Chacanus, visiting Frankish emperor Louis the Pious in Ingelheim in 839. (1b) The Latin Chronicon Salernitanum or "Salerno Chronicle" (anonymous 10th-century chronicle) reports of a diplomatic dispute in 871 between Carolingian emperor Louis the German and Byzantine emperor