The definition of the vassal state has begun to appear in the Western Han Dynasty, Han Gaozu Liu Bang implemented the county system of the Qin Dynasty, and implemented the sub-feudal system in too much of the region, these places around the Beijing division are called "fan states", after the Western Han Dynasty, Korea became a vassal state of China, and the vassal state really had a basic definition.
However, at the end of the Qing Dynasty, the invasion of Western powers forced the vassal states to become colonies, and China also lost a lot of land, but the Qing Dynasty also used the word "China" for the first time when signing the Treaty of Nebuchu with Russia, but until China announced its establishment, it began to use "People's Republic of China", so what is the full name of Japan?
Regarding Japan, there are titles such as the Uighur Kingdom and the Great Japanese Empire, but the Uighur Empire is an ancient title, the Great Japanese Empire is a title of fascism in World War II, and the full name of Japan is "Japan Country" Seemingly simple three words, but it includes Japan's ambitions for thousands of years.
China and Japan also have thousands of years of entanglement, Japan first came to China, was in 607 AD (sui day three years), Japanese emissaries to the Sui Emperor said: "The sunrise of the heavenly son to the book day is nowhere to be unharmed", Japan called the Sui Emperor the sunset heavenly son, which made the Sui Emperor very unhappy, called them barbarians, and let people send them home.
Japan officially established diplomatic relations with China in the 630th year of the Tang Dynasty (Tang Zhenguan 4 years), Japan came in order to learn the culture of the Tang Dynasty, at this time Japan called itself the Kingdom of Wu, after the first time to see the strength of the Tang Dynasty, emperor Shu Ming of the State of Wu had ambitions to invade and occupy the Tang Dynasty, in order to be able to explore the basic forces of the Tang Dynasty, he also sent several diplomatic historians.
Just after the end of the fourth dispatch of the Tang, the new Emperor Tenchi ascended the throne, and in 663, Emperor Tenchi and Baekje launched a large-scale naval battle against the Tang at the mouth of the Baekje River, the Uighur army gathered 40,000 people, more than 1,000 warships, the Tang army gathered 13,000 people, and 170 warships launched a counterattack.
The Tang general Liu Renluo commanded the warships to take advantage of the small number of people to exert great mobility, the Wei army was defeated, this battle was also the first large-scale naval battle between China and Japan, Emperor Tianzhi realized that the Tang Dynasty was powerful, he took the initiative to apologize, and asked the Tang Dynasty to give the name "Japan Country".
The reason why Emperor Tenchi changed the name of the country was also because the Uighurs were too ironic about their height, on the other hand, the Uighurs launched wars, and their image in the Asian region was not good, and changing the name of the country was also hoping to "renew", and the most important thing was that Emperor Tenchi wanted to test the attitude of the Tang Dynasty.
Judging from the fifth and sixth successful dispatches of emissaries by Emperor Tianzhi, the Tang Dynasty did not seem to care about the Battle of Shirae village, since Wu Zetian changed the name of the Tang Dynasty to "Wu Zhou", Japan and the Tang Dynasty had even more contacts, Wu Zetian also gave the "State of Japan", from the root of the "State of Japan", Japan is only using this country name to test China, it is really ambitious.