The first known state in the region was known to Chinese scholars as "Kangju", which was centered on the Syr Darya (also known as the Kang River). Kangju existed from the 1st century BC until the 5th century AD. Its capital was reportedly at or near Bityan. After being subject to several different waves of invaders, Kangju collapsed into several independent states situated mainly in the Syr Darya valley and its tributaries of Keles and Atysi. Its people appear to have Turkified, becoming known as the Kangars.