King of Ceylon (1137-1153). He was the son of Vikkamabāhu II. and succeeded his father to the throne (Cv.lx.88, according to the Dimbulāgala Inscription, his mother was Sundarī). Thus he was the grandson of Vijayabāhu I and of Tilokasundarī, and came, therefore, of Kālinga stock. When he saw the increasing power of the Prince Parakkamabāhu (afterwards Parakkamabāhu I.), Gajabāhu sent for him with many marks of favour and welcomed him at his court. In order to win the king's confidence Parakkama gave his sister Bhaddavati to be his queen, but when he saw that Gajabāhu was becoming suspicious of his power he left Pulatthipura and made preparations to wage war against him. In the campaign that followed, Gajabāhu suffered many reverses and, in the end, fell into the hands of Parakkama's forces. With great difficulty Parakkama saved him from death, but in the meantime Mānābharana managed to get Gajabāhu into his power and cast him into a dungeon. From there he was rescued by Parakkamabāhu and fled to Kotthasāra. Meanwhile, Parakkamabāhu had consolidated his power, and his officers captured Pulatthipura. Gajabāhu, being able to see no other help, implored the monks of Pulatthipura to intercede on his behalf, and, at their request, Parakkamabāhu left to Gajabāhu the enjoyment of his possessions. (This is rather odd, especially in view of the fact that he invited heretical nobles to come to Ceylon, Cv.lxx.53). Gajabāhu took up his abode at Gangātalāka and spent his last days there in comparative peace. As he had no heir and no brothers, he bequeathed his kingdom to Parakkamabāhu, and engraved his will on a stone tablet at Mandalagiri Vihāra. He was cremated at Kotthasāra. (Details of Gajabāhu's reign and his fights with Parakkamabāhu are contained in the Cūlavamsa, particularly in chapters 63, 66, 67, 70, 71). See also Gajabāhukagāmani.