Emperor Suinin
The Mononobe were said to have been descended from Nigihayahi no Mikoto, (饒速日命), a legendary figure who is said to have ruled Yamato before the conquest of Emperor Jimmu. His descendant Mononobe no Toochine (物部十千根), known as the founder of the clan, was given Isonokami Shrine by Yamatohime-no-mikoto, the daughter of Emperor Suinin. He then began using the name Mononobe.