Which prince had an affair with his father's concubine, was deposed and imprisoned?

Luxury and debauchery

During the reign of King Ly Cao Tong, the court was seriously weakened, chaos arose everywhere due to the extravagance and debauchery of the court leaders. Complete Annals of Dai Viet recorded that "the king indulged in debauchery, the administration was unclear, bandits arose like bees, and famine lasted for years."
The book Vietnamese History Summary recorded that the king "was very greedy for wealth and profit, and made selling officials and prisons his main business." Whenever there was a lawsuit, the king often took advantage of it, so "the state's treasury piled up like mountains, while the people complained and resented. Bandits arose like bees."
King Ly Cao Tong was fond of playing, traveling, and feasting. “The king often went out to Hai Thanh palace. Every night, he ordered musicians to play the Ba Lo lute and sing songs in the Cham melody. The sound sounded mournful and sad, and the left and right people who heard the song were moved to tears. Deputy monk Nguyen Thuong told the king, “I see that the poem in the Book of Songs says: The music of a chaotic country sounds like love and longing, because the people of that country are miserable. Now the king is playing around excessively, the government and education are wrong and scattered, the common people are extremely sad. And today, hearing mournful music , isn't that a sign of chaos and loss of the country?”
In 1203, Cao Tong also built a series of palaces and steps in front of the capital. Even in the most chaotic years, when the roads were blocked, the king still liked to wander around, but could not go anywhere, so he ordered the construction of the Ung Phong and Hai Thanh palaces, and every day brought his courtiers, palace maids, and troupes to row small boats as guards as if the king were going somewhere. Then he ordered the wrapping of silk and various sea creatures with beeswax to be put into the pond, then ordered people to wade down and find them, pretending to be objects from the dragon palace, and offer them as offerings...

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