The only military caste of Kerala. They are Vratya Kshatriyas with descent from Nagavansh (The lineage of NÄgas mentioned in Puranas).
They were matrilineal by descent but patriarchal in
nature.
They are the
rare carriers of U1 mtDNA haplogroup in
India.
Most kingdoms in Kerala which popped up after Cheras, were created by Nairs.