According to "Wisdom Library" Sunanda, father of Padumuttara Buddha . He became an ascetic and the Padumuttara Buddha preached to him.
In this life(The Gautama Buddha's time) he was Punna Mantaniputta,Thera Kondanna's nephew, whom the Buddha acknowledged as the foremost preacher of the Dhamma.
[Buddhist Dictionary of Pali Proper Names (excerpts)]
He belonged to a brahmin family of Donavatthu near Kapilavatthu. His mother was
Mantani, sister of Thera Kondanna.
While the Buddha was at Raajagaha, whither he had gone after preaching the
Dhammacakkappavattana Sutta, Thera Kondanna went to Kapilavatthu and ordained Punna.
Thera Kondanna then returned to Raajagaha, whence, having taken leave of the Buddha,
he retired to live on the banks of the Chaddantadaha. But Punna remained in Kapilavatthu,
intent on his practices, and soon after became an arahant. He gathered round him
five hundred clansmen who all became monks, and he taught them the ten bases of
discourse (dasa kathaavatthuuni), which he himself had learnt, and they became
arahants. When they wished to visit the Buddha, Punna sent them on in advance to
Raajagaha, asking them to pay homage to the Buddha in his name. Later, when the
Buddha came from Raajagaha to Saavatthi, Punna visited him and was taught the
Dhamma in the Buddha's own Gandhakuti. Sariputta, hearing of the fame of Punna,
wished to meet him, and went to Andhavana, where Punna was spending his siesta.
Sariputta questioned him on the seven acts of purity, and Punna answered him. The two
monks found great joy in each other's words. The interview with Thera Sariputta is
given in the Rathaviniita Sutta. The two Elders had many things in common.
Punna stands as an excellent example of a monk with a mission and a desire to serve others. He had self-discipline and calm (damupasama), courage (dhiti) and determination (adhiṭṭhāna) and most of all, a passion for the Dhamma (dhammakāma). The Buddha said that those who succeed do so because of their passion for the Dhamma
Later, the Buddha declared Punna to be pre-eminent among those who preached the
*****Ananda became a sotapanna after hearing a sermon by Punna.
Love Buddha's dhamma,