The Kylfings (Old Norse Kylfingar; Estonian Kalevid; Hungarian Kölpények; Old East Slavic Колбяги, Kolbiagi; Byzantine Greek Κουλπίγγοι, Koulpingoi; Arabic al-Kilabiyya) were a people of uncertain origin active in Northern Europe during the Viking Age, roughly from the late ninth century to the early twelfth century. They could be found in areas of Lapland, Russia, and the Byzantine Empire that were frequented by Scandinavian traders, raiders and mercenaries. Scholars differ on whether the Kylfings were ethnically Finnic or Norse. Also disputed is their geographic origin, with Denmark, Sweden and the Eastern Baltic all put forward as candidates. Whether the name Kylfing denotes a particular tribal, socio-political, or economic grouping is also a matter of much debate.