A Borjigin is a member of the Mongol sub-clan, which started with Bodonchar Munkhag of the Kiyat clan. Yesugei's descendants were thus said to be Kiyat-Borjigin. The senior Borjigids provided ruling princes for Mongolia and Inner Mongolia until the 20th century. The clan formed the ruling class among the Mongols and some other peoples of Central Asia and Eastern Europe. Today, the Borjigid are found in most of Mongolia, Inner Mongolia and Xinjiang, and additionally genetic research has shown that descent from Genghis Khan and Amir Timur Barlas is common throughout Central Asia and other regions. Origin and name The patrilineage began with Blue-grey Wolf (Börte Chino) and Fallow Doe (Gua Maral). According to The Secret History of the Mongols, their 11th generation descendant Dobu Mergen's widow Alan Gua the Fair was impregnated by a ray of light. Her youngest son became the ancestor of the later Borjigid. He was Bodonchar Munkhag, who along with his brothers sired the entire Mongol nation. According to Rashid-al-Din Hamadani, many of the older Mongolian clans were founded by members of the Borjigin — Barlas, Urud, Manghud, Taichiut, Chonos, Kiyat, etc. The first Khan of the Mongol was Bodonchar Munkhag's great-great-grandson Khaidu Khan. Khaidu's grandsons Khabul Khan and Ambaghai Khan (founder of the Taichiut clan) succeeded him. Thereafter, Khabul's sons, Hotula Khan and Yesugei, and Khabul's grandson Temujin (Genghis Khan, son of Yesugei) ruled the Khamag Mongol. By the unification of the Mongols in 1206, virtually all of Temujin's uncles and first cousins had died, and from then on only the descendants of Yesugei Baghatur, his brother Daritai, and nephew Onggur formed the Borjigid. According to Paul Pelliot and Louis Hambis, Rashid al-Din Hamadani once explained that "borčïqïn" designated in the Turkic languages a man with dark-blue eyes (), and did so again without mentioning the said language, adding that Yesugei's children and the majority of their own children had had such eyes per coincidence, also recalling that the genie which had impregnated Alan Gua after her husband's death had had dark-blue eyes ("ašhal čašm"). Abu al-Ghazi Bahadur later paraphrased Hamadani by relating that Yesugei's eyes were dark-blue ("شهلا šahlā"), that the Mongols ("Moɣol") called such eyes "borǰïɣïn" (بورجغن), that his sons and most of their descendants had dark-blue eyes ("ašhal"), and that one recognized thus in Yesugei's lineage the characteristic sign of the genie which had visited Alan Gua and had "borǰïɣïn" eyes,