Yuwen Tai (Chinese: 宇文泰; pinyin: Yǔwén Tài) (505/7 – 21 November 556[2]), nickname Heita (黑獺), formally Duke Wen of Anding (安定文公), later further posthumously honored by Northern Zhou initially as Prince Wen (文王) then as Emperor Wen (文皇帝) with the temple name Taizu (太祖), was the de facto ruler and paramount general of the Xianbei-led Chinese Western Wei dynasty, a branch successor state of the Northern Wei.

For the rest of his life, Yuwen endeavored to make Western Wei, then much weaker than its eastern counterpart, a strong state, and after his death, his son Yuwen Jue seized the throne from Emperor Gong of Western Wei, establishing the Northern Zhou dynasty.

Late in 530, apprehensive that Erzhu Rong would eventually seize the throne, Emperor Xiaozhuang ambushed him and killed him in the palace.

Heba made Yuwen the governor of the key Xia Province (夏州, roughly modern Yulin, Shaanxi).

Emperor Xiaowu, hearing of Heba's death, sent Yuan Pi (元毗) to summon both Yuwen and Houmochen to Luoyang.

Houmochen outright refused, and Yuwen persuaded Emperor Xiaowu to allow him to remain in command.

However, Heba Sheng did not arrive at Luoyang, while Yuwen sent forces east, commanded by Li Xian (李賢), to welcome Emperor Xiaowu.

Emperor Xiaowu had engaged in incestuous relationships with three of his cousins, at least one of whom, Yuan Mingyue (元明月) the Princess Pingyuan, followed him to Chang'an.

Yuwen Tai spent much of his effort on preserving existence of Western Wei against repeated attacks led by Gao Huan.

In fall 537, Yuwen led an attack on Eastern Wei and captured Hengnong (恆農, in modern Sanmenxia as well).

The forces engaged at the Battle of Shayuan (沙苑, in modern Weinan, Shaanxi), after Gao rejected advice from his general Hulü Qiangju (斛律羌舉) to directly attack the Western Wei capital Chang'an.

In spring 538, in order to create an alliance with Rouran, Yuwen first had Emperor Wen bestow the title of Princess Huazheng to Yuan Yi (元翌), the daughter of a member of the imperial clan, to marry her to Yujiulü Tahan (郁久閭塔寒), the brother of Rouran's Chiliantoubingdoufa Khan Yujiulü Anagui.

But Yuwen, believing that to be insufficient, requested Emperor Wen divorce his wife Empress Yifu and marry Yujiulü Anagui's daughter.

By summer 538, however, Eastern Wei generals Hou Jing and Gao Aocao had surrounded Luoyang.

Meanwhile, however, Eastern Wei captives in Chang'an heard of the Western Wei defeat and rebelled within the city, led by the general Zhao Qingque (趙青雀), forcing the official Zhou Huida (周惠達), who had been left in charge of Chang'an, to flee the city with the crown prince Yuan Qin.

Under the advice of Lu Tong (陸通), Yuwen quickly returned west and defeated Zhao, suppressing his rebellion.

Around this time, Yuwen also started setting up his headquarters at Hua Province (華州, roughly modern Weinan), not far from Chang'an but maintaining some distance from the capital, incorporate many talented officials and generals into his staff.

A counterattack by Wang, however, killed Murong Shaozong and Liu Fengsheng (劉豐生), temporarily relieving the pressure on Yingchuan.

With Yingchuan having fallen, Yuwen ordered a general withdrawal from the area, and the provinces taken from Hou were retaken by Eastern Wei.

In response, Yuwen launched a major attack on the newly established Northern Qi, reaching Jian Province (建州, roughly modern Jincheng, Shanxi).

While there appeared to be few casualties, Northern Qi was in turn able to make minor border gains in light of Yuwen's withdrawal.

Yujiulü Anagui felt insulted and refused, viewing the Tujue as inferior; in response, Ashina Tumen cut off relations with Rouran.

Yuwen initially agreed to allow Xiao Xun to return to Liang, but instead detained him, releasing him only after Liu again persuaded him to do so, reminding him of his promise.

Yuwen instead compared himself to Yi Yin (伊尹, a legendary regent of Shang dynasty) and Duke of Zhou, apparently disavowing intentions on the throne for the time being.)

Yuwen sent his nephew Yuchi Jiong to attack Xiao Ji's domain (modern Sichuan and Chongqing).

In winter 553, the imperial official Yuan Lie (元烈) formed a conspiracy to kill Yuwen, but the news leaked.

In spring 554, while on a diplomatic mission to Liang (now with Xiao Yi as its undisputed emperor—as Emperor Yuan), the Western Wei official Yuwen Renshu (宇文仁恕, probably Yuwen Tai's relative but relationship is unclear) was slighted by Emperor Yuan, who treated Northern Qi's ambassador with far greater respect.

Soon, Emperor Yuan surrendered, and Western Wei forces gave him to Xiao Cha to be executed.

Most residents of Jiangling were seized as slaves, although eventually most of them were released by Yuwen after he was persuaded to do so by one of the captives, the Liang official Yu Jicai (庾季才).

in the fall of 556, while Yuwen Tai was on a tour of the northern provinces, he became ill at Qiantun Mountain (牽屯山, in modern Guyuan, Ningxia).