Святослав Игоревич
A military organization called "Kölpények" is reported to have existed in Medieval Hungary during the tenth, eleventh and twelfth centuries. Hungarian scholars have proposed that the "Kölpények" were identical with the Kylfings/Kolbiagi. Hungarian sources regard the "Kölpények" as being of Scandinavian origin. They were hired by the early rulers of the House of Arpad, particularly Taksony of Hungary in the 950s, to serve as frontier guards. They fought with their Magyar employers alongside Sviatoslav I of Kiev against Bulgaria and the Byzantine Empire. Alternatively, the "Kölpények" may have been of Pecheneg origin, as there was a Pecheneg tribal group called "Külbej" during roughly the same period.