His birth name was Aranganathan; however, he was known as Nathamuni, which literally means Saint-lord (Nathan - lord, muni - saint).

It is likely that Nathamuni lived for slightly over a hundred years in that region controlled by the Chola kings before they rose to the peak of their greatness.

[10] Though there is difficulty in identifying Nathamuni's date of birth and age, he is considered to have lived during the lifetime of Madhurakavi Alvar's parampara (lineage).

[1] According to Sri Vaishnava tradition, Nathamuni was conversing with his father about the legend of Prabandhams written by the Alvars.

His father, Ishvara Bhattar, exclaimed the Prabandhams were long lost, and that they would be impossible to retrieve unless one had the grace of Narayana.

There, he heard priests singing 10 particular pasurams (hymns) dedicated to Aravamudhan (Sarangapani temple's main deity) by the saint Nammalvar.

[citation needed] The relationship between Nammalvar and Nathamuni is attested by the Guru-paramparā, Divya sūri charita, and Prappannāmŗta.

[1] His grandson was Yamunacharya[3] who was probably named in commemoration of a pilgrimage that Nathamuni took to the banks of the Yamuna along with his son (Iśvara Muni) and daughter-in-law.

[9] It is believed that his other names were Sadamarsana Kula Tilakar, Sottai Kulaththu Arasar, and Ranganatha Acharya.

The other is the Panchratra Agama which belongs to the extensive Tantra literature, believed to have been composed by Narayana himself [citation needed].

The Agama has a peculiar philosophy of its own, the Bhagavata Tradition, which is ancient and is referred to in the Mahabharata and Brahma Sutras of Badarayana.

During that period, a dancing girl sang songs in the same celestial tune (in which Nathamuni set the prabandhams into music) at the court of the Chola king in Gangaikondacholapuram.

During the time of Nathamuni (late 9th century), Uraiyur was the capital of the Chola kings, and Gangaikonda Cholapuram had not been founded yet.

When Nathamuni heard of this incident, he reckoned that it was a mark of high spiritual advancement and called him by the name of Uyyakondar - saviour of the new dispensation.