TURKISH LITERATURE PRIOR TO THE ADOPTION OF ISLAM
Turkish literature was the joint product of the Turkish clans and was mostly oral. The oldest known examples of Turkish writings are on obelisks dating from the late 7th and early 8th centuries. The Orhun monumental inscriptions written in 720 for Tonyukuk, in 732 for Kültigin and in 735 for Bilge Kagan are masterpieces of Turkish literature with their subject matter and perfect style. Turkish epics dating from those times include the Yaratilis, Saka, Oguz-Kagan, Göktürk, Uygur and Manas. The "Book of Dede Korkut", put down in writing in the 14th century, is an extremely valuable work that preserves the memory of that epic era in beautiful language.
Reference: Ministry of Cultural Affairs / The Republic of Turkey
Some selected examples (please click on pictures to enlarge):