Menumorut or Menumorout (Modern ) was the ruler of the lands between the rivers Mureș, Someș and Tisza at the time of the Hungarian conquest of the Carpathian Basin around 900, according to the Gesta Hungarorum, a Hungarian chronicle written after 1150 by an unidentified author, referred to as Anonymus. Historians debate whether Menumorut was an actual ruler or a fictional character created by the author, since the Gesta tells of multiple figures, including Menumorut, who are not identified in any other primary sources, and does not name any of the enemies of the invading Hungarians written of in other contemporary accounts of the invasion. According to Anonymus, Menumorut's duchy was populated primarily with Khazars and Székelys, and he acknowledged the suzerainty of the (unnamed) ruling Byzantine Emperor at the time. Background Early history of the Magyars The most important source of the Magyars' early history is a work known as De Administrando Imperio, written by the Byzantine Emperor Constantine VII around 952. According to the emperor, the Magyars "lived together with" the Khazars "for three years, and fought in alliance" with them for an unspecified time. The text suggests that the Magyars were once subjected to the Khazar Khaganate, the dominant power of the lands between the rivers Dnieper and Volga, but modern historians debate whether their subjection lasted only for a couple of years, as the emperor states, or for a longer period. In the same area, three or four local variants of the Saltovo-Mayaki archaeological culture, which represented semi-nomadic groups, emerged in the western regions of the Eurasian steppes in the second half of the 8th century. Internal strife and attacks by neighboring tribes caused the decline of the Khaganate in the early 9th century. The Magyars were among the Khazars' subject peoples who seceded, settling in the Pontic steppes to the north of the Black Sea. According to Emperor Constantine VII, the Kabars, who "were of the race" of the Khazars, also rebelled against the Khaganate and joined the Magyars. This event occurred before 881, because in that year the Magyars and the Kabars invaded East Francia, according to the longer version of the Annals of Salzburg. The Magyars also intervened in a war between Bulgaria and the Byzantine Empire on the latter's behalf in about 894. The Bulgarians formed an alliance with the Pechenegs, who dwelled in the lands east of the Magyars, and they