which may be based on a 1661 work of Abu al-Ghazi Bahadur Genealogy of the Turks. A proposed grouping of the Turkic, Mongolic, and Tungusic languages was published in 1730 by Philip Johan von Strahlenberg, a Swedish officer who traveled in the eastern Russian Empire while a prisoner of war after the Great Northern War. However, he may not have intended to imply a closer relationship among those languages. Uralo-Altaic hypothesis In 1844, the Finnish philologist Matthias Castrén proposed a broader grouping which later came to be called the Ural–Altaic family, which included Turkic, Mongolian, and Manchu-Tungus (=Tungusic) as an "Altaic" branch, and also the Finno-Ugric and Samoyedic languages as the "Uralic" branch (though Castrén himself used the terms "Tataric" and "Chudic"). The name "Altaic" referred to the Altai Mountains in East-Central Asia, which are approximately the center of the geographic range of the three main families. The name "Uralic" referred to the Ural Mountains. While the Ural-Altaic family hypothesis can still be found in some encyclopedias, atlases, and similar general references, since the 1960s it has been heavily criticized. Even linguists who accept the basic Altaic family, such as Sergei Starostin, completely discard the inclusion of the "Uralic" branch. The term continues to be used for the central Eurasian typological, grammatical and lexical convergence zone. Indeed, "Ural-Altaic" may be preferable to "Altaic" in this sense. For example, Juha Janhunen states that "speaking of 'Altaic' instead of 'Ural-Altaic' is a misconception, for there are no areal or typological features that are specific to 'Altaic' without Uralic." Korean and Japanese languages In 1857, the Austrian scholar Anton Boller suggested adding Japanese to the Ural–Altaic family. In the 1920s, G.J. Ramstedt and E.D. Polivanov advocated the inclusion of Korean. Decades later, in his 1952 book, Ramstedt rejected the Ural–Altaic hypothesis but again included Korean in Altaic, an inclusion followed by most leading Altaicists (supporters of the theory) to date. His book contained the first comprehensive attempt to identify regular correspondences among the sound systems within the Altaic language families. In 1960, Nicholas Poppe published what was in effect a heavily revised version of Ramstedt's volume on phonology that has since set the standard in Altaic studies. Poppe considered the issue of the relationship of Korean to Turkic-Mongolic-Tungusic not settled. In his view, there were three possibilities: (1) Korean did not belong with the other three genealogically, but had been influenced by an