When did Shanghai first become a city?
Shanghai
{'answer_start': array([123]), 'answer_text': array(['746'], dtype=object)}
During the Tang and Song dynasties, Qinglong Town (青龙镇) in modern Qingpu District was a major trading port. Established in 746 (fifth year of the Tang Tianbao era), it developed into what contemporary sources called a "giant town of the Southeast", with thirteen temples and seven pagodas. The famous Song scholar and artist Mi Fu served as its mayor. The port had a thriving trade with provinces along the Yangtze River and the Chinese coast, as well as foreign countries such as Japan and Silla.[2]