According to the New History of Tang Dynasty. According to the Book of Taizong, On May 26, the 23rd year of Zhenguan (649 AD), Emperor Taizong of Tang died of a violent illness caused by taking the elixir of Tianzhu (present-day India) and died in the Hanfeng Hall of the Cuiwei Palace on Mount Zhongli. It turned out that as early as two years ago, that is, in the twenty-first year of Zhenguan (647), it was said that Li Shimin had a "wind disease", was irritable and afraid of heat, and was thirsty, so he let people repair the Cuiwei Palace at the peak of LiShan, and after repairing it, he went there to recuperate.

At this point in time, Wang Xuance, a Tang diplomat who "destroyed one country by one person", sent Tianzhu (India) to return triumphantly.
It is worth saying that Wang Xuance is a remarkable figure.
Before Emperor Taizong fell ill, he sent Wang Xuance to send 30 emissaries to Tianzhu (India), and when Lao Wang arrived in India (ancient India was a federal system, composed of many small countries), there was a coup d'état in the country where the envoys were sent, and the rebels threw Lao Wang and his party into prison.
Lao Wang was extremely depressed, thinking to himself, "It's really unlucky, I'm catching up with the riot, I can't just wait for death." ”
Fortunately, Wang Xuance was resourceful, and when the guards were not paying attention, they blinded the guards, and the group ran out.
The old king did not run to the Tang Dynasty, but ran to tubo, a vassal state of the Tang Dynasty, to borrow troops, and the king of tubo lent Wang Xuance an army of 10,000 people, and the old king took 10,000 horses and used Sun Tzu's art of war to destroy the country with fewer victories and more victories. This is the historical "one man destroys one country" thing.
The old king regained power from the rebels and handed it over to the original king. Then he returned home happily with the spoils of war and the gifts presented by the king to Emperor Taizong.
In addition to this, Wang Xuance also brought back an Indian monk, Narosha PoYu.
After returning to China, Lao Wang came to The Cuiwei Palace, saw Emperor Taizong's sick and crooked appearance, and said, "Your Majesty, it is precisely this time that I brought back a high monk who is more than 200 years old, let him see the disease, right?" ”
As soon as Li Shimin heard about the 200-year-old monk, he decided that he must have the secret recipe for longevity, and quickly said, "Please!" Not long after, the monk came, and Li Shimin looked really extraordinary, with a snow-white beard and a fairy wind Dao bone look, and there was no wrinkle on his face, like a child's face. Emperor Taizong believed in the monk from the bottom of his heart.
The Indian monk learned about the illness, grabbed some unknown powder from the medicine box he carried with him, and then made pills with mercury and cinnabar, and let Lao Wang practice in the alchemy furnace for two days and two nights, and then let Emperor Taizong take it.
The monk said that this was Tianzhu's "resurrection from the dead to immortality".
After practicing well, Taizong ate, not to mention, the first two days really saw good, uncomfortable symptoms such as thirst, irritability, etc. disappeared, Taizong, Lao Wang and the imperial doctors were very happy, the heart said that this time the emperor had been saved.
After concocting and eating three pairs of medicines, after eating the fourth medicine, Emperor Taizong suddenly spat out white foam with his mouth crooked, and died in less than an hour, which frightened Lao Wang and the Indian monks.
Emperor Taizong died, and his son Li Zhi succeeded to the throne, Li Zhi was still kind, and did not blame Lao Wang and the Indian monks, and afterwards lao wang quickly sent the monks back to India.
In fact, where in the world is there a medicine for reviving the dead? How can people eat grains without getting sick? Coupled with the fact that When Emperor Taizong was young, he fought in all directions, fell into a body of pain, and went to the harem of indulgence in old age, which was detrimental to his health, And Emperor Taizong's false fire was too strong, plus the tonic of the monk, such as pouring oil on the fire, Li Shimin was not dead! Without the Indian monks, Li Shimin would have lived a few more days, but...