King of Sri Lanka (1114-1116 A.C.). He was a brother of Vijayabāhu I, who made him ādipāda and gave him Rohaṇa (Cv.lix.12). He married his step-sister Sumittā (Cv.lix.43) and was later made uparāja (Cv.lx.87). On the death of Vijayabāhu, Jayabāhu became king with the help of the Pāndyan faction of the royal family and appointed, “contrary to former custom,” Mānābharaṇa as his uparāja. The latter, however, seems to have been the virtual king; his attempts to attack Vikkamabāhu, the lawful uparāja, ended in disaster, and Vikkamabāhu captured the capital, Pulatthipura, whereupon Jayabāhu retired to Rohaṇa. He lived there as nominal sovereign and died in obscurity (Cv.lxi).