The Turkic migrations were the spread of Turkic tribes and Turkic languages across Eurasia between the 6th and 11th centuries. In the 6th century, the Göktürks overthrew the Rouran Khaganate in what is now Mongolia and expanded in all directions, spreading Turkic culture throughout the Eurasian steppes. Although Göktürk empires came to an end in the 8th century, they were succeeded by numerous Turkic empires such as the Uyghur Khaganate, Kara-Khanid Khanate, Khazars, and the Cumans. Some Turks eventually settled down into sedentary societies such as the Qocho and Ganzhou Uyghurs. The Seljuq dynasty settled in Anatolia starting in the 11th century, resulting in permanent Turkic settlement and presence there. Modern nations with large Turkic populations include Kyrgyzstan, Turkmenistan, Turkey, Azerbaijan, Uzbekistan and Kazakhstan, and Turkic populations also exist within other nations, such as Chuvashia, Bashkortostan, Tatarstan, the Crimean Tatars, the Kazakhs in Mongolia, the Uyghurs in China, the Azeri in Iran, and the Sakha Republic in Siberia. Origin theories Proposals for the homeland of the Turkic peoples and their language are far-ranging, from the Transcaspian steppe to Northeastern Asia (Manchuria). Peter Benjamin Golden listed Proto-Turkic lexical items about the climate, topography, flora, fauna, people's modes of subsistence in the hypothetical Proto-Turkic Urheimat and proposed that the Proto-Turkic Urheimat was located at the southern, taiga-steppe zone of the Sayan-Altay region. According to Yunusbayev et al. (2015), genetic evidence points to an origin in the region near South Siberia and Mongolia as the "Inner Asian Homeland" of the Turkic ethnicity. Similarly several linguists, including Juha Janhunen, Roger Blench and Matthew Spriggs, suggest that Mongolia is the homeland of the early Turkic language. According to Robbeets, the Turkic people descend from people who lived in a region extending from present-day South Siberia and Mongolia to the West Liao River Basin (modern Manchuria). Authors Joo-Yup Lee and Shuntu Kuang analyzed ten years of genetic research on Turkic people and compiled scholarly information about Turkic origins, and said that the early and medieval Turks were a heterogeneous group and that the Turkification of Eurasia was a result of language diffusion, not a migration of a homogeneous population. Hunnic theory The Huns were a nomadic people who lived in Central Asia, the Caucasus, and Eastern Europe, between the 4th and 6th century AD. According to European tradition, they were first reported living east of the Volga River, in an area that was part of Scythia