He was born in Kapilavatthu and of the same Sakyan lineage as his cousin Gotama, the Buddha. His parents were King Amitodana and Queen Gotami.
His noble virtues were as follows:
He served the Buddha as an assistant and a helper.
He served the Buddha for forty years as the Dhamma reciter in accordance with the permission given by the Buddha Himself to preserve His original teaching.
This correct memorization and faithful recitation of the Buddha Dhamma was done by the Venerable Ashin Ananda at the First Buddhist Council of 500 Arahats. As the only permanent personal assistant to the Buddha, he served Him by washing the Buddha’s towel, offering hot and cold water and massaging His feet and hands. He daily cleaned or swept the Jetavana monastery compound after bathing the Buddha in pure water. He always sat near the Buddha to hear every word of the Buddha clearly.
The Buddha gave him the title of honour: One who surpasses all in the matter of being knowledgeable, of being able to retain the Buddha’s teaching in memory for a long time, of being able to interpret the Dhamma correctly, of being able to learn, recite and con the Buddha’s teaching and of looking after the Buddha.
Source : By Ye' Thu Aung