Taisun Khan

Tayisung Khan (or Toghtoa Bukha, Toγtoγa Buqa; Modern Mongolian:Taisun haan) (1416–1453) was a Khagan of the Northern Yuan Dynasty in Mongolia. He was enthroned as the Khagan of the Great Yuan. Under his nominal rule, the western Mongols (Oirats) successfully reunited the entire Mongols and seriously threatened Ming Dynasty of China in the south for the first time since 1409.

Early life
After the emperor Oyiradai’s death in 1425, the internecine war among Oirats led by Mahamud (Bahamu, Batula) and western Mongol clans led by Gulichi's family left the throne of khan vacant for several years as Mongol nobles who held the real power struggled for dominance. The central and eastern Mongol clans, in the meantime, proclaimed Adai as the great khan shortly after Oyiradai’s death in 1425, and the legitimacy of the Oirats, the leading clan of western Mongols was threatened, at least in name.

Toghtoa Bukha (or Toγtoγa Buqa) was the eldest son of Ajai who was a posthumous son of Emperor Elbeg (d.1399) and Öljeitü the Beauty. While wandering with his brothers in western Mongolia, Toghtoa Bukha met Mahamud's son and successor, Toghan taishi, of the Four Oirats. The latter married him to his daughter and wanted to use him as pawn. The Oirats crowned Toghtoa Bukha as their own khagan in 1433. This resulted in half a decade of the simultaneous existence of two khans supported by opposing Mongol clans.

Reign
Toghtoa Bukha Khan was an ambitious khan wanting to obtain real power and recover the former glory of the Yuan Dynasty, which inevitably lead to conflicts with powerful Oirats nobles who held the real power. Although the Oirats shared the same ambition of recover the former glory of Genghis Khan with the new Khan, they were well aware that they must make peace with the Ming Dynasty first so that they could unify all Mongols before their conquest of expansion. The Oirats therefore were careful not to enrage the Ming by not officially proclaiming Yuan which was expulsed by native Chinese from Dadu, and obtained help from the Ming court to defeat the eastern Mongols, killing Adai Khan in the process in 1438.

After the latter's death, Toghan reinstalled Toghtoa Bukha on the throne with the title of Bogd Khagan Tayisung of the Great Yuan before the eight white yurts of Genghis Khan in 1439. Tayisung Khan on the other hand, felt that the Ming was already weakened and not worth worrying about, openly reclaimed the era of the Yuan by proclaiming himself as the Tayisung (Taizong) of the Great Yuan, a move supported by most Mongol populace, except the Oirats, who felt it was not the time yet and they needed time to consolidate their gains first. Fortunately, Ming China was indeed weakened to the point that it could no longer launch any deep strike into the Mongol heartland like Yongle Emperor had done, and all Ming could do was to show its disapproval by calling Tayisung Khan of the Northern Yuan instead of Taizong (太宗) of the Great Yuan.

Tayisung Khan made Toghan's son, Esen, taishi and his younger brother, Agbarjin, jinong soon after Toghan's sudden death in the same year.

During the reign of Tayisung Khan Toghtoa Bukha, Esen subjugated the Jurchens in Manchuria, the Chagatayids in Hami (Qara Del) and the Uriankhais (Tuvans) in Siberia.

Conflict with Ming China
Tayisung Khan was far more inclined towards peaceful relations with Ming China than his commander Esen. He kept a friendly relationship with the Ming court. His taishi, Esen, was very ambitious man who wanted to restore the glory of the Mongol Empire. Esen first focused on Hami Oasis where the another Borjigin prince, descendant of Chagatai Khan, ruled. The prince was an ally of the Ming court. Repeated raids and threats of Esen forced him to surrender in 1448.

The Ming established the Three Guards which consisted of the surrendered Mongols (Doyin Uriyanghkahi, Taining and Fuyu) in the late 14th century. Esen then took Gansu, forcing the Fuyu guard to flee, and appointed his own governor in the area. Tayisung Khan Toghtoa Bukha personally attacked the Three Guards. After that, Esen also plundered the Doyin Uriankhai guard, forcing them to surrender. With the submission of the Three Guards, the Mongol threat to China became direct.

When the Ming refused the Mongols to add the number of Mongol envoys to China and give a Chinese princess, Esen planned to invade Ming China. Tayisung Khan Toghtoa Bukha did not first support it. However, he was induced to led the easternmost force of the Uriankhais (Uriyanghkai) to Liaodong in 1449. He besieged the city and ravaged its outskirts for 40 days while Esen crushing the Ming armies en route to Beijing.

After capturing the Ming Emperor, Zhengtong, and raising the siege of Beijing, the Mongols returned northwards. Tayisung Khan treated the captured Emperor kindly. Esen and he decided to send him back in 1450.

Decline
Tayisung Khan Toghtoa Bukha's consort was the elder sister of Esen who persuaded the Khan to made his sister’s son crown prince so that he would become the future khan. The request was denied, and Tayisung Khan and Esen went to war in 1451. Esen promised Tayisung Khan's brother, Agbarjin, the throne of Emperor instead. Esen and Agbarjin besieged Karakorum where Tayisung Khan stationed. Because most of the eastern Mongols deserted to the Oirats, the Khan's troops were defeated in the land of Turfan and he fled towards the Khentii Khan mountains and the Kherlen River with a few of his entourage. As Tayisung Khan fled, he was killed by his former father-in-law, Tsabdan, in 1453 who later defected to Esen.

Family
Toghtoa Bukha had two younger brothers, Agbarjin and Manduul.

His known wives and children included:
 * An Oirat princess, daughter of Toghan taishi. She bore a son named Abdan.
 * Altagana of the Khorlad tribe. The Khan and her son was Molon (Mulan).
 * Samar taifu who bore Markörgis.