When did other countries in the world begin to call China "Tang people"? Can you tell me why?

The Tang Dynasty was the most prosperous and powerful dynasty in ancient China. Since Emperor Taizong's Zhenguan, he has been expanding his territory and opening up his borders, which has had a great impact on Central Asia, West Asia and South China. The minorities in northwest China called Emperor Taizong "Tiankhan". The prosperity of Wushu can be imagined. During the reign of Emperor Xuanzong of the Tang Dynasty, the national prestige was even stronger, and people from far and near countries sent "visits". Since then, overseas people have added the word "Tang" to everything in China, such as calling China "Tang", China "Tang", China "Tangshan" and so on. This situation continues to this day.

After the demise of the Tang Dynasty, due to the influence of the Tang Dynasty on the world economy and culture, the habit of foreigners calling China "Tangren" has not changed, from the Song and Yuan Dynasties to the Ming and Qing Dynasties. The Biography of True Wax in the Ming Dynasty said: "The people of the Tang Dynasty are also called China people by many fans, and all overseas countries are complete." Today, the older generation of overseas Chinese still like to call themselves "Tangren" and China "Tangshan". As for the places where overseas Chinese live together, almost everyone knows.