Nayar is the feudal landholder and traditional warrior caste, ranking locally as Sudras but performing the functions of the Kshatriyas. It is a Hindu caste of the Indian state of Kerala. Before the conquest of the British in the year 1792, this caste provided militia and land managers to the nobility and royalty of Kerala. At the time of the British rule, this caste became much known in politics, education, medicine and law. Dissimilar to other Hindus, Nayars were traditionally matrilineal and therefore the fathers do not possess any right or obligation on their children. Plural marriage, wherein both women and men could receive multiple `vesting` spouses, was exercised until the nineteenth century. Laws passed in the 1930s which imposed monogamy and provided children complete right of inheritance from the father.

The kingly families of Travancore and Cochin, which claim to be Kshatriya, are descendants of the ancient Chera kings, and were originally Nayars, as were the Samantans or local chieftains. It is the Nayars and the Ezhavas, the largest, most enterprising, and in recent times the most communally aggressive of the Kerala castes, which aroused most speculation regarding their origins.

The Nayars had their own marital customs, their own forms of inheritance, their own art of warfare and their own war goddess, their own cult of ancestor worship, and their own highly original art form, the Kathakali dance drama. As a class of professional warriors who developed to a high level the art of swordsmanship, who formed themselves at time of battle into suicide squads, called chavers, and who despised manual work, leaving their lands to be tilled by tenants or rarely by hired hands, they bore a notable resemblance to the Samurai of Japan, but there is no evidence of an early link between Japan and Kerala, and the resemblance must be regarded as merely a striking example of parallel development.

The similarity of names and of certain customs has suggested that the Nayars may be linked either with the Nagas of Nagaland or with the Newars of Nepal, but it is much more likely that these groups derive their shared characteristics from the ancient Naga people whom the Aryans first encountered when they invaded North India. The people of this vanished North Indian Culture worshipped the Nagas, the serpent deities of the underworld, and they took their name from this cult; the Nayars today preserve the serpent cult. One fact appears certain-not that the Nayars were the first people to settle in Kerala, but that by the time the Brahmins arrived towards the end of the first millennium B.C. they were the ruling race. The Chera kings, the first known rulers of Kerala, were by origin of Nair, not Kshatriya caste, as is clearly shown by their being classed in the Sanskrit epics as of degenerate race, outside the recognized caste system.

The Nayars are Dravidians. The fact that they show differences of temperament and custom from their Tamil and Mysorean neighbours of similar ancestry can doubtless be attributed to the different ways of life which the various groups have followed since the mountains divided them more than two thousand years ago. Generally speaking, the Nayars are lighter in colouring than the Tamils and often they seem more skin in facial structure to North Indians; this may be due to their steady inter-breeding with the Nambudiri Brahmins through the custom of sambandham, a form of morganatic marriage peculiar to Kerala by which the younger sons of Brahmin families could form relationships with Nayar women, the children remaining Nayars and thus introducing a new element into the race.

In Shilappadikaram, there is a description of a warrior tribe which may illuminate one of the transitional phases of Nair history. Shilappadikaram is a literary epoch written by the brother of King Cheran Chenguttuvan, Ilango Adigal. The Nayars held the same belief in the glory of death in battle as the Eiynars, and the goddess who possesses the Eiynars` holy virgin is obviously closely related to Bhadrakali, the manifestation of the consort of Lord Shiva who, as goddess of war, is the patron deity of the Nayar caste and who possesses women and, even more often, men.