Son of Ajātasattu. When Ajātasattu, after the death of his father, paid his first visit to the Buddha and saw the Buddha seated amidst the monks in a scene of perfect calm and silence, his first thought was: "Would that my son, Udāyibhadda, might have such calm as this." (D.i.50).
Buddhaghosa explains (DA.i.153) this thought by saying that Ajātasattu feared that his son might follow his own example and kill him as he had killed his own father. His fears were justified, for he was killed by his son Udāyibhadda, who reigned for sixteen years.
The latter, in his turn, was killed by his son Anuruddhaka (Mhv.iv.1ff. According to Dvy. his son was Munda).
It was in Udāyibhadda's eighth year that Vijaya, king of Ceylon, died, and in his fifteenth year that Panduvasudeva came to the throne (Sp.i.72).
The Dīpavamsa (iv.38; v.97; xi.8) calls him Udaya and the Mahābodhivamsa (p.96), Udayabhadda.
See also Kālāsoka.