Did you know that nearly two centuries after Ramanujacharya popularised the Vishishtadvaita philosophy, in early 14 th Century there was a serious brake up among the followers of Srivaishnava Siddhnatha - the Iyengars - in two bitterly opposing groups called the Vadakalai and Thenkalai sects, with Astadasa-Bhedas, or the Eighteen Points of Doctrinal Differences?

Doctrinal principle of Srivaishnavism developed under the Vishishtadvaita ("qualified non-dualism") Vedanta sub-school of Hindu philosophy, and the followers of this doctrinal principle are popualrly known as Iyengars. This tradition was founded by Nathamuni in the 10th century, furthered by Yamunacharya, and finally evolved and propogated as 'non-dual philospohy', widely attributed to Ramanujacharya in the 11-12th century. However, this tradition split into two denominations in the 14th century - The Vadakalai sect and the Thenkalai sect - though their primary reverence is rooted in Narayana or Vishnu alone. However, they evolved into in two bitterly opposing groups with Astadasa-Bhedas, or the "Eighteen Points of Doctrinal Differences". The perceived prominence given by the sects is to the terse style of Sanskrit traditions by the Vadakalai sect and the lyrical Tamil Prabhandams of the Thenkalai sect. But both follow the philosophy that enunciates 3 entities - God, living and nonliving things; broadly defined as Vishishtadvaita (qualified non-dualism) in Vedanta. 

The northern sect, known as the Vadakalai, (attributed as Srivaishnavas purported to be those acharyas originally living in northern part of the city of Kanchipuram) follow Saint Vedanta Desika (1268-1369 A.D.), a great poet and dramatist in addition to being a great philosopher and theologian, as one of the key guiding paths. The Srivaishnavas living in the southern part of Kanchipuram were known initially as the southern sect or Thenkalai sect who were followers of Ramya-jāmātṛ-muni, Pillai Lokacharya (1205–1311 CE), and finally and emphatically by saint Manavala Mamunigal (1370–1450) also known by the given name Alagiya Manavalan, as a guiding spirit. Manavalan was a major proponent of the Sri Vaishnavism tradition who with his eight disciples, established places of learning to teach the Vishishtadvaita philosophy in Tamilakam.

Apart from the defined 18 esoteric differeences (based on the difference between the path Bhakti (devotion) versus the path of Jnana (knowledge), the two sects exhbit on their forehead Urdvapundram (Namam) in slightly different ways which clearly identify their sect to the common man. The southern culture school or the Thenkalais display on their forehead the thiruman with two white lines and a central srichranam in Kumkum colour and with an extension of white line on the nose, which gives the tiruman a V shape. The central line is called the Sricharanam representing Goddess Lakshmi. The northern culture school, the Vadakalai sect's urdvapundram is a U shape without extension on the nose. But the central sricharanam on the forehead is drawn with yellow turmeric powder. Urdvapundram is clear exhibition of the philosophical belief of a person. Both sects are known by the title "Iyengars". 

However, a principal difference between the two sects is their views on the nature of divine grace - while the Thenkalai holds that devotion is all that is necessary and that god will on his own initiative carry the devotee to salvation, like a cat carrying a kitten, the Vadakalai holds that man has to win god's grace through his efforts and he has to cling on to god, like an infant monkey clinging on to its mother. Another naming convention for the two sects, being the "monkey school" (like baby clinging to the mother) and the "cat school" (purely left to the mercy of the mother who carries its kitten by the mouth). Unlike the Vadakalai, the Tenkalai Iyengar sect reject the Varna or caste system. 

The purported difference of Sricharanam on the forehead seems to be on interpretation of the colour of Lakshmi. Vedas (Sri Suktam) declare her as containing golden complexion (Hiranyavarnam Harinim) that the Vadakalais use literally, while Thenkalais use the symbolic representation with red.

Note: 1. As the Ashtadass Bedha or 18 bedhas or differences between the Thengalai and Vadagalai sects is too elaborate, I am providing the google Url which explains the differences

 <https://ramanujacharya.files.wordpress.com/2015/01/astadasa_bhedas.pdf>

2. Tamialkam as an ancient name for Tamil Nadu is in the News these days

Source: Extracts from various texts related to this subject in English.

Narasipur Char