Yamunacharya (10th c.) according to legend was Ramanuja's teacher.
He was a devotee (bhakta) of the deity
Vishnu, who is said to be the grandson of Nathamuni.
The Nalayira Divyaprabandham, the collected hymns of the
Alvars, a group of poet-saints who lived in southern India between the sixth
and eleventh centuries, was compiled by Nathamuni.
The Alvars were all worshippers of Vishnu, and they conveyed their love via impassioned lyrics sung in Tamil; these hymns are so sacred among southern Indian Vaishnavas (devotees of Vishnu) that they are known as the "Tamil Veda."
Ramanuja, on the other hand, was a philosopher who
collected and systematized this devotional outpouring into a coherent
philosophical viewpoint, and is therefore regarded as the religious community's
founder.
Yamunacharya was thought to be Nathamuni's grandson, and
hence heir to the religious tradition that his grandfather had helped
establish.
The allegation that he was Ramanuja's religious teacher
(guru) is considerably more contested, since it is more probable that Yamuna's
effect on Ramanuja was passed down via Yamuna's pupils.
Still, it is undeniable that these three figures played
pivotal roles in the development of the Shri Vaishnava tradition, and that
Yamunacharya is one of them.
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