In history, Hainan Island was first included in the territory of China during the reign of Emperor Wu of the Han Dynasty. Emperor Wudi of the Han Dynasty did not care about the small size of Hainan Island, and one more piece could be credited with one more deed. However, during the Western Han Dynasty, the dynasty abandoned the island again, and it was not until Emperor Wu of Liang during the Southern and Northern Dynasties five hundred years later that Hainan was reintroduced into the territory.
Why is Hainan being treated as an outcast? After Emperor Wu of han annexed the Nanyue Dynasty, he set his sights on Hainan. Emperor Wu of the Han Dynasty established counties on Hainan Island, but the people of Hainan Island were still primitive Luo Yue people. This made it difficult for the Han Dynasty's ruling institutions to continue on the island, and every few days there would be a rebellion on Hainan Island, so that no official would dare to take up a post on Hainan Island later.
During the reign of Emperor Zhao of Han, Hainan finally became a headache. Emperor Han Zhao had no choice but to lower the ruling rank of Hainan, retaining only one county on the island. The rebellion of the Luoyue people continued, and after the Han Yuan Emperor ascended the throne, he simply abolished the counties on the island, and Hainan Island once again became a barbaric land.
This is also because the rule of the Western Han Dynasty during the Han and Yuan Emperors was already in decline, and it was really powerless to rule Hainan. In terms of Hainan's attitude, the Han Dynasty still allowed Hainanese to cross the sea, and if they wanted to be annexed, the Han Dynasty also welcomed it, but it was not mandatory. From the Eastern Han Dynasty onwards, Hainan Island began to pay tribute to the central government, but because of the lessons of the past, the Eastern Han Dynasty did not set up a ruling body in Hainan.
By the Three Kingdoms era, the State of Wu began to lay out Hainan, but after a major war, the State of Wu suffered heavy losses, and the 30,000 people sent out by Sun Quan were plagued by the miasma of Hainan. It seems that Hainan will take some time. It was not until the time of Emperor Wu of Liang that Hainan became an inseparable part of China.
What do you think?