Turkic

Turkic covers a band of territory running from the Balkans through Anatolia and the Caucasus into Central Asia, western China and Siberia, with around two hundred million speakers and only about forty languages. That ratio is the interesting fact about it. Most families this widespread are also deeply divided, and Turkic is not: its languages remain close enough that a Turkish speaker and an Azerbaijani speaker can hold a conversation, and speakers from opposite ends of the range can often make out the shape of each other's speech. The reason is that the expansion was recent and rapid, driven by the mobility of steppe pastoralism and by a sequence of states, from the Turkic khaganates of the sixth century through the Seljuks and the Golden Horde to the Ottomans.

The earliest substantial texts are the Orkhon inscriptions of eighth-century Mongolia, carved in a runiform script and recording the deeds of khagans in their own language. The shallowness that makes reconstruction easy also makes locating the homeland hard, since the differences that would distinguish one candidate region from another have not had time to build up. Two outliers are worth noting. Chuvash, on the Volga, is divergent enough that it is treated as a primary branch on its own, and Khalaj in Iran preserves features lost everywhere else. Both are small, both are the least like the rest, and both therefore do disproportionate work in any reconstruction.

Few language families have carried as many religions in as short a time. The oldest layer recoverable from Turkic sources is Tengrism, the veneration of Tengri as the sky, attested directly in the Orkhon inscriptions where a khagan attributes his rule to Tengri's favour, and accompanied by a body of practice around sacred mountains, ancestor spirits and shamanic specialists. In the eighth century the Uyghur khaganate adopted Manichaeism as a state religion, the only state anywhere ever to do so, and Manichaean texts in Old Uyghur are among the most important surviving witnesses to that religion.

Uyghur communities in the Tarim basin were also substantially Buddhist, and translated a considerable Buddhist literature. From the tenth century onwards Turkic peoples took up Islam in large numbers, and the Turkic-speaking dynasties then carried it into Anatolia and, through the Delhi sultanate and the Mughals, into South Asia, which is how a family from the Siberian forest edge became one of the principal vehicles of Islamic expansion. Some Turkic-speaking peoples of Siberia, and the Chuvash on the Volga, kept older practice into the modern period, and Tengrism has been revived in several Turkic republics since 1991.