Emperor Kōgen

was the 8th emperor of Japan, according to the traditional order of succession. Historians consider Emperor Kōgen to be a legendary person; and the name Kōgen"-tennō" was created for him posthumously by later generations.
No certain dates can be assigned to this emperor's life or reign. The conventionally accepted names and sequence of the early emperors were not to be confirmed as "traditional" until the reign of Emperor Kammu, who was the 50th monarch of the Yamato dynasty. 
The "Gukanshō" records that Kōgen ruled from the palace of "Sakaihara-no-miya" at Karu in what will come to be known as Yamato province.
Traditional history.
Kōgen is almost certainly a legend. The "Kojiki" records only his name and genealogy. The "Nihonshoki" includes Kōgen as the seventh of .
Kōgen was the eldest son of Emperor Kōrei.
Some scholars question the existence of the first nine emperors. These critics consider Kōgen's grandson (Emperor Sujin) to be the earliest to have actually existed.
Events of Kōgen's life.
The absence of information about Kōgen does not imply that no such person ever existed. Very little information is available for study prior to the reign of the 29th monarch, Emperor Kimmei. 
The Abe clan are said to have descended from a son of Emperor Kōgen. 
After his death.
This emperor's official name after his death (his posthumous name) was regularized many centuries after the lifetime which was ascribed to Kōgen. 
The actual site of his grave is not known. According to the Imperial Household Agency, this emperor is venerated at a memorial Shinto shrine ("misasagi") at Nara.