and half Denisovan, and lived some 90,000 years ago, was also found within the latter cave. Russia was home to some of the last surviving Neanderthals, from about 45,000 years ago, found in Mezmaiskaya cave. The first trace of an early modern human in Russia dates back to 45,000 years, in Western Siberia. The discovery of high concentration cultural remains of anatomically modern humans, from at least 40,000 years ago, was found at Kostyonki–Borshchyovo, and at Sungir, dating back to 34,600 years ago—both in western Russia. Humans reached Arctic Russia at least 40,000 years ago, in Mamontovaya Kurya. The Kurgan hypothesis places the Volga-Dnieper region of southern Russia and Ukraine as the urheimat of the Proto-Indo-Europeans. Early Indo-European migrations from the Pontic–Caspian steppe of Ukraine and Russia spread Yamnaya ancestry and Indo-European languages across large parts of Eurasia. Nomadic pastoralism developed in the Pontic–Caspian steppe beginning in the Chalcolithic. Remnants of these steppe civilizations were discovered in places such as Ipatovo, Sintashta, Arkaim, and Pazyryk, which bear the earliest known traces of horses in warfare. The genetic makeup of speakers of the Uralic language family in northern Europe was shaped by migration from Siberia that began at least 3,500 years ago. In classical antiquity, the Pontic-Caspian Steppe was known as Scythia. In late 8th century BCE, Ancient Greek traders brought classical civilization to the trade emporiums in Tanais and Phanagoria. In the 3rd to 4th centuries CE, the Gothic kingdom of Oium existed in southern Russia, which was later overrun by Huns. Between the 3rd and 6th centuries CE, the Bosporan Kingdom, which was a Hellenistic polity that succeeded the Greek colonies, was also overwhelmed by nomadic invasions led by warlike tribes such as the Huns and Eurasian Avars. The Khazars, who were of Turkic origin, ruled the steppes between the Caucasus in the south, to the east past the Volga river basin, and west as far as Kyiv on the Dnieper river until the 10th century. After them came the Pechenegs who created a large confederacy, which was subsequently taken over by the Cumans and the Kipchaks. The ancestors of Russians are among the Slavic tribes that separated from the Proto-Indo-Europeans, who appeared in the northeastern part of Europe years ago. The East Slavs gradually settled western Russia in two waves: one moving from Kiev towards present-day Suzdal and Murom and another from Polotsk towards Novgorod and Rostov. From