From The Dhamma Encyclopedia
Kondanna was a brahmin who first came to prominence as a youth due to his mastery of the vedas and was later appointed as a royal court scholar of King Suddhodana of the Sakyas in Kapilavatthu. There Kondanna was the only scholar who unequivocally predicted upon the birth of Prince Siddhattha that the prince would become an enlightened Buddha, and vowed to become his disciple. Kondanna and four colleagues followed Siddhattha in six years of ascetic practice, but abandoned him in disgust after Siddhattha gave up the practice of self mortification. Upon enlightenment, Siddattha gave his first Dhamma talk to Kondanna's group. Kondanna was the first to comprehend the teaching and thus became the first bhikkhu and arahant.
Kondanna was regarded as the foremost of the five initial disciples of the Buddha and later travelled around India spreading the Dhamma. Among his notable converts was his nephew Punna, whom the Buddha acknowledged as the foremost preacher of the Dhamma. In his final years, he retreated to the Himalayas and predeceased the Buddha.
Kondanna's previous lives are described in many accounts in Buddhist literature. These accounts show that he had vowed in previous existences to be the first to comprehend the Dhamma when it was to be proclaimed by an enlightened Buddha. They also document that the seeds of his relationship with Buddha as the first arahant were sown in previous existences in which they had crossed paths.