Black Sea–Caspian Steppe language and the Northeast Caucasian languages are related to Hurrian and Urartian. This implies that the mountaineers of the Caucasus have been in their present location for a very long time. According to the most common theory the Indo-European languages originated on the steppes north of the Caucasus and Black Sea. Some time before 3000 BC the Maikop culture appeared in Circassia and Kabardia. It is noted for its excellent gold and silver work. North on the steppe was the Yamnaya culture which was probably Indo-European. Around 1000 BC there was a bronze-age Koban culture in the Kabardian area which
Caspian Sea closed basin, with its own sea level history that is independent of the eustatic level of the world's oceans. The level of the Caspian has fallen and risen, often rapidly, many times over the centuries. Some Russian historians claim that a medieval rising of the Caspian, perhaps caused by the Amu Darya changing its inflow to the Caspian from the 13th century to the 16th century, caused the coastal towns of Khazaria, such as Atil, to flood. In 2004, the water level was below sea level. Over the centuries, Caspian Sea levels have changed in synchrony with the estimated discharge