He was the seventh son of Prince Toneri, a son of Emperor Temmu.[5] His father died when he was at the age of three, and he was given no rank nor office of the court.
In the older Japanese documents, he was often referred as the "unthroned emperor" (廃帝, Haitei).
7 September 758 (Tenpyō-shōhō 2, 1st day of the 8th month): In the 10th year of Kōken's reign, the empress abdicated. The succession (senso) was received by her adopted son. Then Emperor Jimmu is said to have acceded to the throne (sokui).[6] This was confirmed in ceremonies.[7]
764 (Tenpyō-hōji 8): Junnnin was sent in exile to Awaji.[9]
10 November 765 (Tenpyō-jingo 1, 23rd Day of the 10th Month): Former Emperor Junnin died in exile.
Junnin caused grain storage centers (Jōheisō) to be established in the provinces. The government stored rice from the years of good harvests. This rice was used to control higher prices when harvests of rice were not good. The Jōheisō were abolished during the Kamakura period.[10]
After his death
The actual site of Junnin's grave is known.[1] This emperor is traditionally venerated at a memorialShintoshrine (misasagi) at Awaji.[11]