<P> An alternate theory states that the system was introduced by the Nambudiri Brahmins . Although Brahmin influences had existed in the area since at least the 1st - century AD, there was a large influx from around the 8th - century when they acted as priests, counsellors and ministers to invading Aryan princes . At the time of their arrival the non-aboriginal local population had been converted to Buddhism by missionaries who had come from the north of India and from Ceylon . The Brahmins used their symbiotic relationship with the invading forces to assert their beliefs and position . Buddhist temples and monasteries were either destroyed or taken over for use in Hindu practices, thus undermining the ability of the Buddhists to propagate their beliefs . The Brahmins treated almost all of those who acceded to their priestly status as shudra, permitting only a small number to be recognised as kshatriya, these being some of the local rulers who co-operated with them . Certainly by the 11th - century, this combination of association with kings and invaders, and with the destruction or take - over of Buddhist temples, had made the Brahmins by far the largest group owning land in the region and they were to remain so until very recent times . Their introduction of Sanskrit and their melding of it with the local Tamil language to form Malayalam was also striking . Their dominating influence was to be found in all matters: religion, politics, society, economics and culture . </P> <P> By the late 19th - century, the caste system of Kerala had evolved to be the most complex to be found anywhere in India . There were over 500 groups represented in an elaborate structure of relationships and the concept of ritual pollution extended not merely to untouchability but even further, to unapproachability . The system was gradually reformed to some degree, with one of those reformers, Swami Vivekananda, having observed that it represented a "mad house" of castes . The usual four - tier Hindu caste system, involving the varnas of Brahmin (priest), Kshatriya (warrior), Vaishya (business person, involved in trading, entrepreneurship and finance) and Shudra (service person), did not exist . Kshatriyas were rare and the Vaishyas were not present at all . The roles left empty by the absence of these two ritual ranks were taken to some extent by a few Nairs and by non-Hindu immigrants, respectively . </P> <P> The Nairs identify themselves as being in many subgroups and there has been debate regarding whether these groups should be considered as subcastes or a mixture both of those and of subdivisions . There have been several attempts to identify these various groups; most of these were prior to the end of British governance in India but Kathleen Gough also studied the issue in 1961 . These analyses bear similarities to the Jatinirnayam, a Malayam work that enumerated 18 main subgroups according to occupation, including drummers, traders, coppersmiths, palanquin bearers, servants, potters and barbers, as well as ranks such as the Kiriyam and Illam . Although the Jatinirnayam did not itself distinguish any particular subgroups as ranking higher, subsequent attempts at classification did do so, claiming the various occupations to be traditional ones and stating that only the higher ranked groups were soldiers . Anthropologists, ethnologists and other authors believe that the last name of a Nair was a title which denoted the subgroup (vibhagam) to which that person belonged and indicated the occupation the person pursued or was bestowed on them by a chief or king . These names included Nair itself, Kurup, Menon, and Pillai . </P> <Table> <Tr> <Th_colspan="5"> (show) Nair subdivisions in descending order of rank according to standard descriptions, compiled by CJ Fuller in 1975 </Th> </Tr> <Tr> <Th> Ranking </Th> <Th> Jatinirnayam </Th> <Th> Aiya (1906) </Th> <Th> Iyer (1912) </Th> <Th> Innes (1908) </Th> <Th> Gough (1961) </Th> </Tr> <Tr> <Td> </Td> <Td> Kiriyam </Td> <Td> Kiriyam </Td> <Td> Kiriyam </Td> <Td> Kiriyam </Td> <Td> Kiriyam </Td> </Tr> <Tr> <Td> </Td> <Td> Illam </Td> <Td> Illam </Td> <Td> Illam </Td> <Td> Purattu Charna </Td> <Td> Purattu Charna </Td> </Tr> <Tr> <Td> </Td> <Td> Svarupam </Td> <Td> Svarupam </Td> <Td> Svarupam </Td> <Td> Akattu Charna </Td> <Td> Akattu Charna </Td> </Tr> <Tr> <Td> </Td> <Td> Padamangalam </Td> <Td> Padamangalam </Td> <Td> Purattu & Akattu Charna </Td> <Td> Illam </Td> <Td> Pallicchan </Td> </Tr> <Tr> <Td> 5 </Td> <Td> Tamil Padam </Td> <Td> Tamil Padam </Td> <Td> Menokki </Td> <Td> Mutta </Td> <Td> Illam </Td> </Tr> <Tr> <Td> 6 </Td> <Td> Itasseri </Td> <Td> Itasseri </Td> <Td> Maran </Td> <Td> Taraka </Td> <Td> Vattakkatan </Td> </Tr> <Tr> <Td> 7 </Td> <Td> Maran </Td> <Td> Maran </Td> <Td> Padamangalam </Td> <Td> Ravari </Td> <Td> Otattu </Td> </Tr> <Tr> <Td> 8 </Td> <Td> Chempukotli </Td> <Td> Chempukotli </Td> <Td> Pallicchan </Td> <Td> Anduran </Td> <Td> Anduran </Td> </Tr> <Tr> <Td> 9 </Td> <Td> Otattu </Td> <Td> Otattu </Td> <Td> Vattakkatan </Td> <Td> Otattu </Td> <Td> Asthikkuracchi </Td> </Tr> <Tr> <Td> 10 </Td> <Td> Pallicchan </Td> <Td> Kalamkotti </Td> <Td> Chempukotti </Td> <Td> Pallicchan </Td> <Td> Veluttetan </Td> </Tr> <Tr> <Td> 11 </Td> <Td> Matavan / Puliyath </Td> <Td> Vattakkatan </Td> <Td> Otattu </Td> <Td> Urali </Td> <Td> Vilakkittalavan </Td> </Tr> <Tr> <Td> 12 </Td> <Td> Kalamkotti / Anduran </Td> <Td> Pallicchan </Td> <Td> Itasseri </Td> <Td> Chempukotti </Td> <Td> </Td> </Tr> <Tr> <Td> 13 </Td> <Td> Vattakkatan / Chakkala </Td> <Td> Asthikkuracchi </Td> <Td> Anduran </Td> <Td> Vattakkatan </Td> <Td> </Td> </Tr> <Tr> <Td> 14 </Td> <Td> Asthikkuracchi / Chitikan </Td> <Td> Chetti </Td> <Td> Asthikkuracchi </Td> <Td> Asthikkuracchi / Chitikan </Td> <Td> </Td> </Tr> <Tr> <Td> 15 </Td> <Td> Chetti </Td> <Td> Chaliyan </Td> <Td> Tarakan </Td> <Td> Kulangara </Td> <Td> </Td> </Tr> <Tr> <Td> 16 </Td> <Td> Chaliyan </Td> <Td> Veluttetan </Td> <Td> Vilakkittalavan </Td> <Td> Itasseri </Td> <Td> </Td> </Tr> <Tr> <Td> 17 </Td> <Td> Veluttetan </Td> <Td> Vilakkittalavan </Td> <Td> Veluttetan </Td> <Td> Veluttetan </Td> <Td> </Td> </Tr> <Tr> <Td> 18 </Td> <Td> Vilakkittalavan </Td> <Td> </Td> <Td> Chaliyan </Td> <Td> Vilakkittalavan </Td> <Td> </Td> </Tr> <Tr> <Td> 19 </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> Kaduppattam </Td> <Td> </Td> </Tr> <Tr> <Td> 20 </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> Chaliyan </Td> <Td> </Td> </Tr> </Table>

What is the difference between nair and menon