The principality of Chach had a square citadel built around the 5th to 3rd centuries BC, some  south of the Syr Darya River. By the 7th century AD, Chach had more than 30 towns and a network of over 50 canals, forming a trade center between the Sogdians and Turkic nomads. The Buddhist monk Xuanzang (602/603? – 664 AD), who travelled from China to India through Central Asia, mentioned the name of the city as  (). The Chinese chronicles ''History of Northern Dynasties'', ''Book of Sui'', and ''Old Book of Tang'' mention a possession called   ("stone") or   with a capital of the same name since the fifth century AD.