The Old Turkic script (also known as variously Göktürk script, Orkhon script, Orkhon-Yenisey script) is the alphabet used by the Göktürk and other early Turkic Khanates during the 8th to 10th centuries to record the Old Turkic language.
The oldest written records are found upon stone monuments in Central Asia, in the Orhon, Yenisey and Talas regions within the boundaries of present-day Mongolia. These were erected to Bilge Kaghan (735), Kültigin (732), and the vizier Tonyukuk (724-726). Apart from these, there are some one hundred inscriptions of various sizes mentioned by the Swedish army officer Johan von Strahlenberg. The first to read them and publish his results was the Danish Turcologist Wilhelm Thomsen, while the Russian Turcologist (of Prussian extraction) Wilhelm Radloff contributed in a major way to the deciphering of the script. The perfection of the language used in these records, which document the social and political life of the Gokturk Dynasty, proves that Turkish, as a language of letters, has been in use from very ancient times.
In later periods many forms of writing would appear: Nestorian writing in the northeast, Sogd, Uighur, and Pali writings in the southeast, Manichaean texts. In Brahman writing, and from the 11th centuary onward, Arabic script for Islamic texts. In addition, depending on the region in which they lived, the Turks have employed Suryani, Armenian, Georgian and ancient Greek alphabeths, producing literary works which have transmitted the Turkish culture up to the present day. After the waning of the Gokturk state, the Uighurs produced many written texts that are among the most important source works for the Turkish language. The Uighurs produced many written texts that are among the most important source works for the Turkish language. The Uighurs abondened shamanism(the original Turkish religion) in favor of Buddhism, Manichaeanism and Brahminism, and translated the pious and philosophical works of all of them into Turkish. Examples are Altun Yaruk, Mautrisimit, Sekiz Yükmek, Huastunift, etc. These were collected by european turcologists in Turkische Turfan-Texte.
The Kokturk (Gokturk) inscriptions, together with Uighur writings, are in a language called by scholars Old Turkish. This term refers to the Turkish spoken, prior to the conversion to Islam, on the steppes of Mongolia and Tarim basin. With the emergence of the Cagatay Dynasty, which came about when the Empire of Genghis Khan was divided among his sons, a new wave of Turkish literature was born and flowered under the influence of Persian literature. It reached its pinnacle with the works of Ali Sir Navai in the 15th century. The Turkish of Turkey that developed in Anatolia and across the Bosphorus in the times of the Seljuks and Ottomans was used in several valuable literary works prior to the 13th century. The men of letters of the time were, notably, Sultan Veled, the son of Mevlana Celaleddin-i Rumi, Ahmed Fakih, Seyyad Hamza, Yunus Emre, a prominent thinker of the time, and the famed poet, Gulsehri.
The earliest known examples of writing in any Turkic language were found in the Orkhon river valley in Mongolia during the 19th century. They date from the early 8th century AD and the script in which they are written is known as the Orkhon alphabet, or the Old Turkic script, the Göktürk script, or the Orkhon-Yenisey script. Inscriptions dating from the later 8th century AD in a slight variant of the Orkhon alphabet, known as Yenisei or Siberian runes, have also been found around Yenisei and other parts of Siberia. Because of a superficial resemblance to the runic charecters of the Elder Futhark, the alphabet is also known as Orkhon or Turkic runes. This resemblance is probably a result of the writing materials used - most inscriptions are in hard surfaces, such as stone or wood, and curved lines are difficult to inscribe in such surfaces.
The Orkhon alphabet is thought to have been derived from or inspired by a non-cursive version of the Sogdian script. By the 9th century AD, the Orkhon and Yenisei alphabets were replaced by the Uighur alphabet, which developed from the cursive version of the Sogdian script.