Jia Sidao (August 25, 1213 – October 1275), courtesy name Shixian, was a Chinese government official. He was a chancellor of the late Song dynasty of China, and the younger brother of a concubine of Emperor Lizong, who had the special favor of Emperor Duzong. Jia Sidao took part in a land nationalization program in the 1260s and was involved during the Mongol Yuan invasion of the Song, especially during the Battle of Xiangyang and the siege of Ezhou. He was assassinated by a Song dynasty court-designated sheriff charged with his custody in 1275.

Jia Sidao was born in 1213, to Jia She and Lady Hu; Hu was a renounced concubine of Jia She. Jia She died when Jia Sidao was 11. By the time he earned his jinshi at the age of 25 in 1238 AD, his elder sister was already a concubine of the Emperor Lizong with the rank of guifei.^[1]

Jia Sidao was a chancellor from 1260 to 1273 during the late Song dynasty of China.^[2] According to History of Song, he is reported to have risen to the rank of chancellor because his sister, Lady Jia, was a favored concubine of the Emperor Lizong.^[1]

Jia is best known for his intervention in the Battle of Xiangyang, where he hid the true situation (Xiangyang was under heavy attack from the Mongols and would almost certainly fall without reinforcements) from the Song court. During the Mongol invasion, there was intense political infighting among Song generals, with Jia Sidao and members of the Lü Wenhuan's family actively opposing the Song general Li Tingzhi.^{[citation needed]}

Jia enjoyed the special favor of the Emperor Duzong. Being Jia's junior by 27 years, the Emperor used to stand up upon his entrance, called him "teacher" (though Jia was not an imperial degree holder, and never held such a formal post), and is said^{[by whom?]} to have knelt in tears on one occasion,^[when?] begging Jia Sidao to remain in office.^{[citation needed]}

Jia pioneered a policy of land nationalization highly unpopular among the Confucians, who favored low taxes and a small role for the state. The land survey, endorsed by several other officials, was undertaken ca. 1262. It was driven by pressing military needs, and by rampant concentration of land in the hands of powerful landlords, who were often high-ranking court officials. In 1263, the gongtian (公田, "public field," a northern Song feature) system was re-introduced, whereby the amount of land held by individuals was restricted, and the excess land being classified as gongtian. The income from gongtian was then used to supplement military expenditure; this system functioned for the next 12 years. Jia's land reform activities went even further than those undertaken by Wang Mang during the Han dynasty, as under Wang Mang, the state monopolized only 1/3 of the excess land holdings, and at least provided some minimal compensation.^[3] In contrast, Jia's reforms offered no compensation; another of Jia's aims was to abolish the hedi policy, and reduce the amount of paper money in circulation, as under the hedi policy, with the government purchasing more grain, they had to issue more paper money, resulting in rising inflation.^{[citation needed]}

During the siege of Ezhou, Jia Sidao's offer to Kublai Khan to partition China was rejected, however due to Mongke's failure of the Yunnan campaign, and a redirection of massive troops to the Ezhou frontier, Kublai decided to offer Jia Sidao a deal that he would return to Karakorum for his kurultai due to the succession dispute with Ariq Böke.^[4]

Later, at the Battle of Yihu, Jia Sidao, while leading an army of 130,000, panicked and escaped the battlefield in a small boat. The troops, seeing that their commander had abandoned them, retreated hastily; the result was a defeat whereby the remnants of the Song army were routed, allowing the Mongols to advance on the capital, Lin'an. As a result of this defeat, Jia Sidao was demoted from the post of chancellor.^{[citation needed]}

The possibility of executing Jia Sidao for his court failures was hotly debated in Lin'an (now Hangzhou) on the verge of its fall. Dowager Empress Xie objected to this as a cruelty, but issued progressively severe decrees of banishment and property confiscation that included Jia Sidao and his family under the pressure of the public.^{[citation needed]} Ultimately, in 1275,^[1] Jia Sidao was assassinated by a court-designated sheriff, Zheng Huchen (郑虎臣), who had been charged with his custody.^[5] Whether the execution was court-sanctioned remains unclear.^[6]

• Song Dynasty
• Song-Yuan Wars

• History of Song, volume 474