Why did so many foreigners live in Chang 'an in ancient times?

Because it was the capital of the Tang Dynasty Empire, according to the geomantic omen of China, it belonged to Long Mai. The location of Chang 'an has been moved for historical reasons, but it is generally located near Xi 'an and Xianyang in Shaanxi, China.

Because 17 dynasties and political powers established their capitals in Chang 'an successively, and 2 1 dynasties and political powers established their capitals in Chang 'an successively, the total capital establishment time exceeded 1200 years. It is the most influential capital in the history of China, and also the longest established capital. Ranked first among the four ancient capitals in China, among many dynasties with Chang 'an as their capital, the Han Dynasty, Sui Dynasty and Tang Dynasty were the most prosperous times in China's history, when Chang 'an had become an international metropolis.

During 65438 BC+095-25 AD and 580-900 AD, ancient Chang 'an was the largest city in the world.

In its heyday, Chang 'an has always been the center of the world, attracting a large number of foreign envoys and worshippers.