Wikipedia
Giocangga ( Manchu: ; ) (died 1582) was the grandfather of Nurhaci, the man who was to unify the Jurchen peoples and begin building what later became the Manchu state. Both he and his son Taksi went to the aid of Nurhaci's uncle Atai (阿台 Ātái) whose city was being besieged by a rival Jurchen chieftain Nikan Wailan (ᠨᡳᡴᠠᠨ ᠸᠠᡳᠯᠠᠨ; 尼堪外蘭 Níkān Wàilán), who promised the governance of the city to whoever would kill Atai. One of Atai's underlings rebelled and murdered him. Both Giocangga and Taksi were originally under the command of the Ming general Li Chengliang who was siding with Nikan Wailan. In the mist of battle Li thought they had mutinied as they were left in the battlefield. They were killed in the aftermath by Nikan Wailan.
His temple name was Jǐngzǔ (景祖).
In 2005, a study led by a researcher at the British Wellcome Trust Sanger Institute suggested that Giocangga might be a direct male-line ancestor of over 1.5 million men, mostly in northeastern China. This was attributed to Giocangga's and his descendants' many wives and concubines. It was estimated that the average man in the time of Giocangga would have only 20 living descendants . Gioncangga's descendants in the patrilineal line are concentrated among several ethnic minorities who were part of the Manchu Eight Banners system, and are not found in the Han Chinese population.