What empire had more that one million people lived in Chang'an its capital city?

The Tang Dynasty, which ruled from 618 to 907 AD, had its capital in Chang'an (modern-day Xi'an) and is estimated to have had a population exceeding one million people at its height. Chang'an was a cosmopolitan hub, serving as a center for trade, culture, and politics, attracting merchants and travelers from across Asia and beyond. The city's layout and infrastructure reflected the sophistication of Tang society.