Nephew of Devánampiyatissa. He was the king's chief minister, and led the embassy which was sent to Asoka soon after Devánampiyatissa ascended the throne (Mhv.xi.20). Asoka conferred on him the title of Senápati (Mhv.xi.25). It is said that he had fifty five elder and younger brothers who all joined the Order at Cetiyagiri at the end of a sermon by Mahinda on the Vassúpanáyikakhandha (Mhv.xvi.10). This was before the commencement of the rainy season, but elsewhere (Mhv.xviii.3; perhaps here we have to deal with two different traditions) it is said that Arittha was sent in the month of Assayuja - after the pavárana, when the rains were over - to Pátaliputta to fetch Sanghamittá and the Bodhi tree from the court of Asoka, and that, he agreed to go only on condition that he should join the Order on his return. The king consented, and, his mission successfully concluded, he entered the Order with five hundred others and attained arahantship (Mhv.xix.5, 12, 66). He died in the reign of Uttiya (Mhv.xx.54).
The Samantapásádiká (Sp.i.102ff) gives an account of a recital (sangíti) held in Ceylon by Mahá Arittha. The scene was the parivena of the minister Meghavannábhaya in the Thúpáráma, where sixty eight thousand monks were assembled. A seat, facing south, was provided for Mahinda, Arittha's seat, the dhammásana, facing north. Arittha occupied this seat at Mahinda's request, and sixty eight Mahá-theras, led by Mahinda, sat around him. Devánampiyatissa's younger brother, Mattábhaya Thera, with five hundred others, were present in order to learn the Vinaya, the king also being present. When Arittha began his recital of the Vinaya, many miracles occurred. This was on the first day of the pavárana ceremony in the month of Kattika.
Mahá Arittha's chief disciples were Tissadatta, Kálasumana and Díghasumana (q.v.).