Wikipedia
Vanniyars are said to be born from flame in a mythological period. The origin of this caste states that a Rishi or Saint known as Jambu Maharishi is the father of the group in Tamil Nadu and spread across south India. Their main job during ancient times was safe guarding the country, forming the Army and other groups. They broadly fall in the group of Kshatriyar. They are widely spread groups all over Tamil Nadu, Andhra, Kerala and Karnataka(Joshua Project).
The Vania people are also called Bania or Mahajan. The word Vania is derived from 'Vaniji', which means 'trader' in Sanskrit. The Vania community has gotras such as Agarwal, Dasora, Dishawal, Kapol, Nagori, Vagada, Modh and Nagar.
Many of these names are based on the names of the place they are from. The Agrawal, though they are settled mainly in North Gujarat, take their name from the Agar Town. The Jharola live in Eastern Gujarat and the come from Jalor of Rajashthan and Maharashtra. The titles used by the Vania are Shah, Shroff, Parikkh, Chokshi, Seth and Gandhi.
The Vania community consists of two religious divisions, namely Vaishnava and Jain. Most of the groups of Vania are split into Visha meaning twenty and Dasha or ten. These subdivisions are further divided into Ekda and Bagda. The Bagda mostly live in villages, while Ekda live in villages and towns. They have an organization called the Mandal to look after the temples and the community's property.
Business, trade, jewellery-making and agriculture are the traditional occupations of the Vania. Floor painting and folk songs represent the Vania's art and culture. The naming of the newborn ritual is performed by a Jangam priest by putting a thread around the infant's neck.
The Vania are Hindu by religion. They are Vaishnavite and devotees of Shrinathji. A section of them are from the Jain community. The Vania maintain intercommunity linkages with the Brahman, Valand, Soni and other communities through trade and service. The Vania in the state of Maharashtra are mostly the followers of the Lingayat Cult.
In Northern Kerala, this community is being called Vaniyan Nair. Adding Nair to name is not denotifying the nair caste, but as a "title" honoured by the then ruling Nair kings to Vaniya community members who supply oil to their state as a token of appreciation. This is often misused or people get confused for as a caste. This let the way for some Malayalam speaking vaniya members having nair surname titles getting absorbed into the larger Nair community, thus losing the identity of their old generation created.
Northern Kerala is a testimony to this scenario. The Vaniya of North Malabar have their own place of worship called Muchilot Kavu. The presiding deity is Muchilot Bhagavathi . They have an annual festival running for 3–4 days called as Kaliyattam.Thousand of people are fed food for all the 3–4 days. In some Muchilot this festival takes place once in a decade or more and is called as Perumkaliyattam .This attracts lakhs of people.
The Vaniyan Nair community also runs the Thunchath acharya educational and charitable Trust in Kannur. The well-known Thunchath Acharya Vidyalayam, a Senior Secondary CBSE affiliated school at Eda Chovva, Kannur, functions under this trust.