Title given to chiefs from Nair caste
Kaimal is an aristocratic title or position granted by various Rajas to powerful Nair families in Kerala.
The word "Kaimal" originated from "Kai," meaning "the hand," signifying power in medieval Kerala.
Kaimals are considered one of the highest castes in South India, along with Samantha Varmas, Karthavs, Thirumalpad, Pillais, Kurups, Nambiars, etc.
Kaimals identify themselves as a Nair Subcaste. There are many references recorded in various historical documents. They are the Jenmi and Naduvazhi of Kerala.
Several well known families have borne the title, including the Thachudaya Kaimal, Kaimals of Koratti, Angi and Pondicherry.
Many Kaimal families are also part of Kshatriya Kshema Sabha along with Nair Service Society. 
Subcaste.
Koima + Alu: Koima (Dominant) Alu (Person) means 'The person who dominates.' This was the title given to the feudal chiefs under the Kerala kings.
The Kaimals were the title awarded to individuals from different Nair subcastes.
There are different Nair Kaimals: (1) Thachudaya Kaimal, (2) Vakkayil Kaimal, (3) Vakkathu Illam Kaimal, (4) Kiriyathil Nair Kaimal, (5) Illathu Nair Kaimal, (6) Moothedathu Kaimal, (7) Eleyedathu Kaimal, (8) Thengumpillil Kaimal, (9) Aalangattu Kaimal, (10) Kodancheri Kaimal, (11) Koratty Kaimal, (12) Anchi Kaimal, (13) Ner Nintha Kaimal, and (14) Chuzhandu Vanna Kaimal, to name a few of the better-known Kaimal families.
Kaimals of Cochin
The Kaimals of Cochin are direct descendants or sons of Tulu Cheraman Perumal stemming from his different wives, a revered Chera king who ruled the state during the medieval period from Kodungallur. They were members of the Samantha Kshatriya and the Vellayama Nair (Kiriyathil Nair) subcaste.
Kaimals of Malabar
The Keralolpathi states that the title of Kaimal was given to the sons of Kolathiri, rulers of Kannur, whom the Keralolpathi refers to as Cheraman Vadakkan Perumal. They were descendants of the Mushika royal family of Kshatriya and belonged to the Samanthan community. Over time, they discontinued the practice of using the title Kaimal and adopted the titles Raja and Varma.
Kaimals of Travancore
The Thachudaya Kaimals were ruling chiefs of Travancore, nominated by the Travancore Raja from the Noble Nair families. They were from the Samantha Nair and Illathu Nair subcastes.
The Dutch in Cochin.
On 26 October 1662, the rulers of Kochi successfully defeated the Portuguese who wanted to change the statue of Kochi from that of an ally to that of a vassal. They exploited the rivalry between the Dutch and the Portuguese, and made the Dutch their ally in the war against the Portuguese forces. The Kochi kings fought this battle with the assistance rendered by the Anchi Kaimals.
T. I. Poonen says ;templatestyles src="Template:Blockquote/styles.css" / ;It may be mentioned that one of the important causes of Dutch success in Cochin was the loyal co-operation they received from the Anchi Kaimals or five lords of whom the most important was Cheranellular Kartha.
Regional rulers.
Some regional rulers such as Koratty Kaimal were served and protected by trained non-Nair warriors as well.
Territorial rulers titled Kaimal and Kartha ran parallel administrative systems by challenging kings.
 Many of them were very powerful and even Raja sought help from foreign powers such as the Portuguese to conquer them.
References.
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