Thread:Univero/@comment-24166893-20190726014534

Actually, while it was during the Tang dynasty that the Empire of Yamato was a tributary state to China (until the An Lushan Rebellion of the mid 8th century), Japan was once again a tributary state of China approximately 600 years ago. During the weakest Shogunate in Japanese history, that of the Ashikaga Shogunate of the 14th-16th centuries. The shogun Ashikaga Yoshimitsu (1358-1408) accepted vassalage under the Ming. He was the only Japanese shogun to do so and future generations of samurai and later ultranationalists condemned him.

On the other hand China never conquered Japan, and yes the Japanese did conquer a good chunk of China but that was during a period when China was seriously disunited with warlords and Triads, Nationalists and Communists, Muslim separatists, and European/Russian occupiers in various parts of its country. Japan sooner or later would have had to leave China, they had neither the manpower, natural resources, or industrial capability to complete the conquest. By the time they decided to attack Pearl Harbor the Japanese were for all intents and purposes in a quagmire in China.

Besides the Han Chinese dynasties  were never interested in conquering Japan, it was the Mongols who tried to conquer Japan with a huge fleet of Chinese & Korean ships transporting a Mongol & Chinese army. The Tang Dynasty could have invaded Japan in the 7th century during the Tang-Baekje War. A Japanese armada of over 600 ships sent to help their Korean allies (Beakje) against th Chinese and their Korean allies (Silla) was annihilated by the Chinese fleet in the Battle of Baekgang. It was the greatest naval disaster in Japanese history and left the islands defensless. The Japanese panicked and fearing invasion from China built a serious of fortifications on the southenr islands.

Later during the weak Ashikaga Shogunate, the Ming dynasty likewise could have conquered the islands. This was when China had naval supremacy in the Far East, with a huge navy of hundreds of warships that sent a total of seven expeditions of dozens to over a 100 ships (the largest several times larger than Christopher Columbus' ship) to Southeast Asia and then the Indian Ocean (reaching Africa and Arabia). Simply put Japan, like the Philippines and Indonesian archipelago had nothing that China really wanted, except tribute.

Whenever the Chinese waged wars of conquest it was on mainland states with productive agricultural land and/or natural resources that were adjacent (first the Yangtze River and the eastern Yellow River, then Sichuan and the area south of the Yangtze,  and later Yunnan,  northern Vietnam, southern Manchuria, and Korea). They would also campaign to control strategically important oasis / caravan cities in the Silk Road (the Gansu Corridor, Xinjiang, and  eastern Central Asia), and to establish a buffer between China and steppe nomadse (e.g. Inner Mongolia, the Altai Mountains of northern Xinjiang and eastern Mongolia, and the Mongolian plateau).

At different times in history they conquered the steppe nomads (Xiongnu (possibly the Huns), Khitan Mongols, Gokturk (united Turks), and Eastern Turks). At other times  they only succeded in breaking their power (Xiongnu and Northern Yuan Mongols). Sometimes they ended up paying tribute to the steppe nomads (Xiongnu, Toba Wei, Gokturks, Khitan Mongols, and Four Oirat Mongols). At other times they lost parts of northern China to the steppe nomads (Toba Wei and Khitan Mongols) and in one case all of China fell to the steppe nomads (Yuan Mongols).

The Han Chinese dynasties of the Han and Tang paid tribute at the beginning, and would end up later conquering the steppe nomads. The Song dynasty paid tribute from the beginning and ended up being conquered by the Mongols. The Ming dynasty overthrew the Mongol Yuan dynasty, expelled the Mongols from China, then broke the power of the resurgent Northern Yuan but later would at certain periods pay tribute to the Four Oirat Mongols (Western Mongols)

See below regarding the Ming and Ashikaga Shogunate:

https://www.japantimes.co.jp/news/2014/02/15/national/history/once-upon-a-time-china-anointed-a-king-of-japan/

The Tang-Baekje War:

https://en.wikipedia.org/wiki/Baekje%E2%80%93Tang_War

https://en.wikipedia.org/wiki/Battle_of_Baekgang 