Was from the village of Kahna, 21 km southwest of Lahore on the road to Firozpur. He had an humble origin, his father Khushal (Singh), earning his living by selling grass and wood at Lahore. Jai Singh received amrit or initiatory rites of the Khalsa at the hands of Nawab Kapur Singh and joined the jatha or roving band of Amar Singh Kingra. It is commonly believed that name of the band, Kanhaiya, was derived from the name of Jai Singh's village, Kahna, although another explanation connects it with the Sardar's own handsome appearance which earned him the epithet (Kahn) Kanhaiya, an endearing title used for Lord Krisna.

Jai Singh seized a part of Riarki comprising the district of Gurdaspur and upper portions of Amritsar. His first headquarters were at his wife's village, Sohian, 15 km from Amritsar, from where he shifted to Batala and thence to Mukerian. His territories lay on both sides of the rivers Bean and Ravi. A contemporary Muslim historian, Qazi Nur Muhammad, wrote in 1765 that Jai Singh Kanhaiya had extended his territory up to Parol, about 70 km southeast of Jammu, and that he worked in collaboration with Jassa Singh Ramgarhia, both sharing between them the territory of Batala.

The hill chiefs of Nurpur, Datarpur and Siba became jai Singh's tributaries. In 1774, jai Singh built a katra or bazaar at Amritsar called Katra Kanhaiyan.

In October 1778 he, with the help of Mahan Singh Sukkarchakkia and Jassa Singh Ahluwalia, drove away Jassa Singh Ramgarhia to the desert region of Hansi and Hissar. In 1781, Jai Singh and his associate, Haqiqat Singh, led an expedition to Jammu and received a sum of three lakh of rupees as a tribute from Brij Raj Dev of Jammu.
According to Khushwaqt Rai, Jai Singh died in 1793 at the age of 81. Control of the Kanhaiya misl passed into the hands of his daughter-in-law, Sada Kaur, his son, Gurbakhsh Singh, having predeceased him.

Source: Encyclopaedia of Sikhism, Harbans Singh