Sri Ramanuja was born at Sriperumbudur, according to tradition in 1017 CE, to Asuri Kesava Somayaji and Kanthimathi. As a young man he studied Vedanta in Kanchi under Yadavaprakasa, but he often found that his teacher's explanations of the Upanishads made the Lord less than He is. Their differences grew, and in time Ramanuja left him.
In Kanchi he served Thirukkachi Nambi, who fanned Lord Varadaraja every day and, the tradition says, spoke with Him. Through Thirukkachi Nambi the Lord gave Ramanuja six answers that settled his questions. Alavandar's disciples then became his teachers. Periya Nambi gave him pancha samskaram at Madhurantakam, and Thirukkoshtiyur Nambi, Periya Thirumalai Nambi, Thirumalai Andan and Alwar Thiruvarangapperumal Arayar each taught him a part of what Alavandar had left. He took sannyasa at Kanchi and came to be called Yatiraja, king of ascetics.
The tradition remembers him best at Thirukkoshtiyur. Thirukkoshtiyur Nambi made him come eighteen times before teaching him the meaning of the sacred mantra, and told him to keep it to himself. Ramanuja climbed the temple gopuram, called out to everyone who wished to be saved, and gave them its meaning openly. When his acharya asked whether he knew he could suffer for this, Ramanuja answered that he would gladly suffer if so many could be saved. Thirukkoshtiyur Nambi embraced him and called him Emperumanar, "our Lord".
Fulfilling Alavandar's wish, Ramanuja wrote the Sri Bhashyam on the Brahma Sutras, along with the Gita Bhashyam, Vedartha Sangraham, Vedanta Deepam and Vedanta Saram. In the Gadya Trayam he put into words his own surrender to Thayar and Perumal at Srirangam. He set the temple worship at Srirangam in order. When a Chola king turned against him he lived for many years at Thirunarayanapuram (Melkote), and later returned to Srirangam.
According to tradition he lived for 120 years. His thirumeni is worshipped at Srirangam to this day, and the whole tradition carries his name — Emperumanar Darsanam, the Ramanuja Sampradaya.