Chang'an is a city located in China's Shaanxi Province. Historically, it served as the capital city for several Chinese dynasties, including the Western Han and the Tang, from 202 BC to 907 AD.
During its period as a capital, Chang'an was recognized at various times as the largest city in the world. Following these periods of prominence, the city's name was changed, and it adopted the modern name of Xi'an during the Ming dynasty.