The earliest known Turkic inscriptions are the two monumental Orkhon inscriptions found in modern Mongolia. Erected in honour of the prince Kul Tigin and his brother Emperor Bilge Khan, and dating back to some time between 732 and 735, they constitute another important early record. After the discovery and excavation of these monuments and associated stone slabs by Russian archaeologists in the wider area surrounding the Orkhon Valley between 1889 and 1893, it became established that the language on the inscriptions was the Old Turkic language written using the Orkhon script, which has also been referred to as “Turkic runes” or “runiform” due to a superficial similarity to the Germanic runic alphabets.
With the Turkic expansion during Early Middle Ages (c. 6th–11th centuries), peoples speaking Turkic languages spread across Central Asia, covering a vast geographical region stretching from Siberia to Europe and the Mediterranean. The Seljuqs of the Oghuz Turks, in particular, brought their language, Oghuz Turkic—the direct ancestor of today’s Turkish language—into Anatolia during the 11th century. Also during the 11th century, an early linguist of the Turkic languages, Mahmud al-Kashgari from the Kara-Khanid Khanate, published the first comprehensive Turkic language dictionary and map of the geographical distribution of Turkic speakers in the Compendium of the Turkic Dialects (Ottoman Turkish: Divânü Lügati’t-Türk).