In 628, while Ilig Khan and his nephew Töles were at war, someone at the Tang court proposed to rebuild the old Long Wall and send people to man the frontier.[1] The emperor Taizong refused.[1] He named four signs that the Göktürk state was about to fall. He told his ministers that he would take the state for them, so a wall was not needed.[1] The Zizhi tongjian enters the exchange under the day jiwei of the ninth month, when the Göktürks had raided the frontier.[2] Less than two years later the Tang armies destroyed the eastern khaganate.[3]

Background

Taizong had sworn peace with Ilig at the Wei bridge in 626.[3] In 627 the tribes north of the desert rose against Ilig. A great snow also killed the Göktürk herds.[3] Taizong’s ministers urged him to strike, but he refused. A common man had to keep his word, he said, and the lord of the world all the more.[3]

The Zizhi tongjian records the debate of that year in two steps.[4] First Taizong asked Xiao Yu and Changsun Wuji what to do.[4] Ilig and his ministers, he said, were benighted and cruel, and their ruin was certain. To strike would break the new oath, but not to strike might lose the moment.[4] Xiao Yu advised an attack.[4] Changsun Wuji answered that the enemy had not crossed the frontier. To break faith and burden the people, he said, was not the war of a true king.[4] The emperor held back.[4]

Then Zheng Yuanshu, the chief of the Court of State Ceremonial, came back from the Göktürks.[4] The rise and fall of the steppe peoples, he said, could be read in their sheep and horses.[4] Now the Göktürk people were starving and their beasts were thin. This was a sign of ruin within three years.[4] Taizong agreed. Even so, he refused to attack until the Göktürks gave him a cause.[4]

The four signs

The Xin Tang Shu gives the speech in full.[1] Taizong said that among the Göktürks frost had fallen in high summer, five suns had risen together, three moons had shone at once and a red vapour had filled the plains.[1] The Göktürks saw these calamities and did not cultivate virtue. In Taizong’s words, this meant that they did not fear Heaven.[1] That was the first sign.

Next, he said, they moved their camps without order, and most of their herds died. This meant that they did not use the land.[1] By their custom the dead had been burned. Now they buried them all under mounds.[1] That, Taizong said, was to turn against the command of their fathers and to slight the spirits.[1] The last sign was the quarrel with Töles, in which kinsmen attacked and destroyed one another.[1] A people with these four faults, the emperor concluded, would perish. He would take their state for his ministers rather than build walls.[1]

The Zizhi tongjian gives a shorter version without the list.[2] In it Taizong says that the Göktürks suffered one disaster after another. Ilig did not fear these disasters and mend his ways. Instead he grew crueller, and his own flesh and blood fought each other.[2] Their ruin was a matter of days, and the emperor was about to sweep the desert clean for his ministers. There was no need to wear the people out building distant barriers.[2]

Ilig’s government in the Xin Tang Shu

The Xin Tang Shu goes on from the speech to the khan’s government.[1] The customs of the Göktürks had been plain and simple.[1] Ilig took a Chinese scholar, Zhao Deyan, valued his talent and trusted him. Zhao gradually came to control the state.[1] The khan gave the government to the hu, the Sogdians. He kept his own kinsmen at a distance and raided China every year, until his people could bear no more.[1] The hu were greedy and fickle. Orders changed constantly, famine came year after year and the levies were heavy. As a result the tribes fell further away.[1] The Zizhi tongjian places Zhao Deyan’s rise in 627 and says that he changed many of the old customs.[4]

The third sign concerns the Göktürk funeral. The Zhou Shu describes the custom Taizong appealed to. The dead man was burned with the horse he had ridden and the things he had used, and the ashes were buried later in the season.[5] Six years after the speech Taizong had Ilig himself burned east of the Ba river, by the custom of his people.[3]

The next year

In the eighth month of 629 Zhang Gongjin, the governor-general of Daizhou, set out the case for war in six points.[2] Ilig indulged his desires, killed loyal men and favoured flatterers. The Xueyantuo and other tribes had all risen. Töles and two shads had fallen into disgrace and had nowhere to turn.[2] Frost had come early north of the frontier and food was short. Ilig kept his kin at a distance and trusted the fickle hu. The many Chinese living in the north had gathered in the mountains and would rise when an army came.[2] Ilig had asked for a marriage alliance and still supported the rebel Liang Shidu. Because of this, Taizong named Li Jing commander against him on the day dinghai.[2] The campaign of the winter of 629 and 630 followed.[3]

The four signs are known only from the court that went to war. They served that court as its argument for war.

References

  1. ^ a b c d e f g h i j k l m n o p Xin Tangshu (New Book of Tang), juan 215
  2. ^ a b c d e f g h Zizhi tongjian (Comprehensive Mirror in Aid of Governance), juan 193
  3. ^ a b c d e f Jiu Tangshu (Old Book of Tang), juan 194
  4. ^ a b c d e f g h i j k Zizhi tongjian (Comprehensive Mirror in Aid of Governance), juan 192
  5. ^ Zhou Shu (Book of Zhou), juan 50

Sources

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Cite this article

Yavuz, Emre-E. “Taizong's Speech on the Signs of Ruin (628).” Turkic Atlas, revised 28 October 2026. https://turkicatlas.org/events/taizongs-speech-628/

Last revised: 28 October 2026