Dayan Khan

Dayan Khan (/ˈdaɪən xɑːn/; Mongolian: Даян Хаан [ˈtajɴ ˈχaːɴ]), born Batumöngke (Middle Mongol: [b̥atʰʊ̆møŋkʰĕ], Modern Mongol: [paʰtmɵŋx]; Chinese: 巴圖蒙克 Bātúméngkè; 1472–1517) was a khagan of the Northern Yuan dynasty, reigning from 1480 to 1517. During his rule, he reunited the Mongols under Chinggisid supremacy. His reigning title, "Dayan", means "the whole" or "long lasting" in Mongolian language as he was the longest reigning khagan of the unified Mongols.

Dayan Khan eliminated Oirat and the great Khan of chagatai Altnaa power and abolished the taishi system used by both local and foreign warlords. Dayan Khan's victory at Dalan Tergin [ja] reunified the Mongols and solidified their identity as Chinggisid people. His decision to divide the six tumens of Eastern Mongolia as fiefs for his sons created decentralized but stable Borjigin rule over the Mongolian Plateau for a century.

Batumongke was the son of Bayanmongke (Bayanmunh) (fl. 1470–1480) the Bolkhu jinong (or crown prince/viceroy) of the Borjigin clan and Shiker Taiko (Shihir Taihu) of the Uriyangkhai in Mongolia. His paternal grandmother, Sechen, was a daughter of Esen Tayshi of the Oirats. Although Bolkhu and his family suffered through life's darkest hours during the reign of Esen and the internal conflict of the Northern Yuan dynasty, they were welcomed by his uncle (brother) Manduul Khan (r. 1465–1467) soon after his coronation.

Batumongke's father and his uncle Manduul had come to blows due to warlords' convictions, and Bayanmongke had fled and been murdered. Manduul's taishi Ismayil [ja; zh] (also known as Isama) then took his wife Shikher and properties. In order to save Batumongke's life Shiker gave her child to the Bakhay family to nurse him. However, Temur-Qadag of the Tangud (already Mongolicized) took the child from Bakhay. Because of his Borjigin blood, Batumongke was well taken care of by the Mongol commoners and minor nobles.

At the sudden death of Manduul Khan in 1467, Batumongke was five years old. Later he was adopted by Mandukhai Khatun, the widow of Manduul Khan. When Mandukhai's loyalists brought back Batumongke, he was suffering echinococcosis. Mandukhai had him treated and the boy recovered soon.

As a direct descendant of Kublai Khan (r. 1260–1294), Mandukhai had him ascend to the throne at the age of eight at the Royal shrine kept by the Chakhar and he became known by the title "Dayan Khan". When he was aged nineteen, she married him, and retained great influence over court and military. They reunified the Mongol retainers of the former eastern region of the Mongol Empire. The Oirats were defeated by the military skill of Mandukhai and control was reclaimed over the Eastern Mongols. Batumongke and his queen Mandukhai led Mongol armies in 1483 against Ismayil Taishi who after the imperial victory over him fled to Hami where he was killed by other Muslims and Turco-Mongols. Dayan Khan's mother Shiker was brought back and given the title taikhu (empress dowager). However, she did not live long enough after that. The imperial power was supported by Unubold (Naybolad), the descendant of Hasar who was the brother of Genghis Khan, and the tribes ruled by descendants of Genghis Khan's brothers were allied. Most of the Four Oirats remaining in Mongolia surrendered and provided troops. Only Khoosai of the Tumed rejected Dayan Khan's supremacy but was defeated in turn.

The most important achievement of the couple was their defeat of the war-like Oirats who had previously revolted against the rule of the Borjigin Emperors since the 14th century. By 1495, Batumongke won the Three Guards (Doyin Uriankhai, Ujiyed and Fuyu guard), tributaries of the Ming dynasty, and had them incorporated into his Six tumens.

While the Golden Horde lost its power in 1480, Mongol raids on Ming borderlands became virtually constant. Under Dayan Khan they reached a new level of organization. Dayan Khan intended to maintain good relations with Ming dynasty at first. His envoys were sent to sign open-trade contract with gifts, but one of them was killed by the Ming court, so he launched military expeditions into the Ming China. Dayan Khan as a mature ruler had no interest in joining the Ming's tribute system.