Why do historians have limited indigenous written sources for early Central Asian history?

Historians face a significant challenge regarding the history of Central Asia due to the scarcity and relative lateness of indigenous written records. The first aboriginal sources written in a Turkic language do not appear until the 8th century CE, and comparable material remains largely unavailable until the 13th century.1

Because of this lack of early indigenous documentation, much of what is known about the region comes from the written accounts of surrounding sedentary civilizations, such as those in China, Greece, Rome, and the Arab and Persian worlds. These external sources are often heavily biased against the nomadic peoples of Central Asia, complicating the objective study of their history.1

While many early Central Asian societies relied on oral tradition to preserve their history, beliefs, and clan migrations, these forms of record-keeping do not provide the same type of evidence as written manuscripts. Consequently, determining the specific languages or internal perspectives of many early nomadic empires remains difficult, and historians must often exercise caution to avoid making unwarranted assumptions about these cultures.231