A king who lived in the beginning of this present age.
The Páli Chronicles (Mhv.ii.1ff.; Dpv.iii.1ff.; MT. 122ff.; also J.ii.311; iii.454, etc.) mention him as the original ancestor of the Sákiyan family, to which the Buddha belonged, and gives a list of the dynasties from his day to the time of the Buddha, to prove that the line was "unbroken."
Mahásammata belonged to the Solar Race and is identified with the Bodhisatta, who was born among men after sojourn in the Brahma worlds (MT. 121 f). He was called Mahásammata, because, on the arising of wickedness in the world, he was chosen by the people (sannipatitvá samaggajátehi mahájanchi sammannitvá kato Mahásammato; MT.122; cp. D.iii.92f.; Mtu.i.248; DhSA. 390, 392) to show indignation against and disapproval of those worthy of blame. In return for his services, he was given a portion of their harvest.
It is said (J.iv.192) that in the dynasty of Mahásammata the idea of meting out punishments, such as torture, fining, expulsion, was unknown. These were invented later with the advance of civilisation!
The Vimánavatthu Commentary (p.15) explains that Mahásammata is the name given in the sacred books (sásane) for Manu. Some, at least, of the Ceylon kings traced their descent from Mahásammata. See, e.g., Cv.xlvii.2.