The tradition traces its roots to the primordial start of the world through Vishnu, and to the texts of Vedic era with both Shri and Vishnu found in ancient texts of the 1st millennium BCE particularly to the puranas, Upanishads and the Bhagavad Gita.
The historical basis of Shri Vaishnavism is in the syncretism of two developments. The first is Sanskrit traditions found in ancient texts such as the Vedas and the Agama (Pancaratra), and the second is the Tamil traditions found in early medieval texts (Tamil Prabandham) and practices such as the emotional songs and music of Alvars that expressed spiritual ideas, ethics and loving devotion to god Vishnu. The Sanskrit traditions likely represent the ideas shared in ancient times, from Ganges river plains of the northern Indian subcontinent, while the Tamil traditions likely have roots in the Kaveri river plains of southern India, particularly what in modern times are the coastal Andhra Pradesh, Karnataka and Tamil Nadu region.
The tradition was founded by Nathamuni (10th century), who combined the two traditions, by drawing on Sanskrit philosophical tradition and combining it with the aesthetic and emotional appeal of the Bhakti movement pioneers called the Alvars. Shri Vaishnavism developed in Tamil Nadu in the 10th century, after Nathamuni returned from a pilgrimage to Vrindavan in north India (modern Uttar Pradesh).
Nathamuni's ideas were continued by Yamunacharya, who maintained that the Vedas and Pancaratras are equal, devotional rituals and bhakti are important practices. The legacy of Yamunacharya was continued by Ramanuja (1017-1137), but they never met. Ramanuja, a scholar who studied in an Advaita Vedanta monastery and disagreed with some of the ideas of Advaita, became the most influential leader of Shri Vaishnavism. He developed the Visistadvaita ("qualified non-dualism") philosophy.
Around the 18th century, the Shri Vaishnava tradition split into the Vatakalai ("northern culture", Vedic) and Tenkalai ("southern culture", Bhakti). The Vatakalai placed more emphasis on the Sanskrit traditions, while the Tenkalai relied more on the Tamil traditions. This theological dispute between the Vedic and Bhakti traditions traces it roots to the debate between Shrirangam and Kanchipuram monasteries between the 13th and 15th century. The debate then was on the nature of salvation and the role of grace. The Bhakti-favoring Tenkalai tradition asserted, states Patricia Mumme, that Vishnu saves the soul like "a mother cat carries her kitten", where the kitten just accepts the mother while she picks her up and carries. In contrast the Vedic-favoring Vatakalai tradition asserted that Vishnu saves the soul like "a mother monkey carries her baby", where the baby has to make an effort and hold on while the mother carries. This metaphorical description of the disagreement between the two sub-traditions, first appears in the 18th-century Tamil texts, but historically refers to the foundational ideas behind the karma-marga versus bhakti-marga traditions of Hinduism.
Along with Vishnu, and like Shaivism, the ultimate reality and truth is considered in Shri Vaishnavism to be the divine sharing of the feminine and the masculine, the goddess and the god. Shri (Lakshmi) is regarded as the preceptor of the Shri Vaishnava sampradaya. Goddess Shri has been considered inseparable from god Vishnu, and essential to each other, and to the act of mutual loving devotion. Shri and Vishnu act and cooperate in the creation of everything that exists, and redemption. According to some medieval scholars of Shrivashnava theology, states John Carman, Shri and Vishnu do so using "divine knowledge that is unsurpassed" and through "love that is an erotic union". But Shri Vaishnavism differs from Shaivism, in that Vishnu is ultimately the sole creator, preserver and destroyer of the universe while Shri Lakshmi is the medium for salvation, the kind mother who recommends to Vishnu and thereby helps living beings in their desire for redemption and salvation. In contrast, in Shaivism, the goddess (Shakti) is the energy and power of Shiva and she is the equal with different roles, supreme in the role of creator and destroyer.
Shri Vaishnavism's philosophical foundation was established by Ramanuja, who started his Vedic studies with Yadava Prakasha in an Advaita Vedanta monastery. He brought Upanishadic ideas to this tradition, and wrote texts on qualified monism, called Vishishtadvaita in the Hindu tradition. His ideas are one of three subschools in Vedanta, the other two are known as Adi Shankara's Advaita (absolute monism) and Madhvacharya's Dvaita (dualism).
Ramanuja's Vishishtadvaita asserts that Atman (souls) and Brahman are different, a difference that is never transcended. God Vishnu alone is independent, all other gods and beings are dependent on Him. However, in contrast to Dvaita Vedanta philosophy of Madhvacharya, Ramanuja asserts "qualified non-dualism", that souls share the same essential nature of Brahman, and that there is a universal sameness in the quality and degree of bliss possible for human souls, and every soul can reach the bliss state of God Himself. While the 13th- to 14th-century Madhvacharya asserted both "qualitative and quantitative pluralism of souls", Ramanuja asserted "qualitative monism and quantitative pluralism of souls", states Sharma. The other philosophical difference between Madhvacharya's Vaishnavism Sampradaya and Ramanuja's Vaishnavism Sampradaya, has been on the idea of eternal damnation; Madhvacharya believed that some souls are eternally doomed and damned, while Ramanuja disagreed and accepted the Advaita Vedanta view that everyone can, with effort, achieve inner liberation and spiritual freedom (moksha).
According to Shri Vaishnavism theology, moksha can be reached by devotion and service to the Lord and detachment from the world. When moksha is reached, the cycle of reincarnation is broken and the soul is united with Vishnu, though maintaining their distinctions, in Vaikuntha, Vishnu's heaven. Moksha can also be reached by total surrender and sharanagati, an act of grace by the Lord.
God, according to Ramanuja's Shri Vaishnavism philosophy, has both soul and body; all of life and the world of matter is the glory of God's body. The path to Brahman (Vishnu), asserted Ramanuja, is devotion to godliness and constant remembrance of the beauty and love of personal god (saguna Brahman, Vishnu), one which ultimately leads one to the oneness with nirguna Brahman.