Complex sentence: This timeline is a supplement of the main article Uyghur it refers to critical period (400-900) in the cultural formation of the Uyghur nation, as they transitioned from a minor Turkic tribe to an empire.
Split into simpler sentences: This timeline is a supplement of the main article Uyghur. Dealing with the centuries between 400 and 900 AD, it refers to a critical period in the cultural formation of the Uyghur nation, as they transitioned from a minor Turkic tribe to an empire.