JASVANT SIṄGH, RĀJĀ (1775-1840), succeeded his father, Rājā Hamīr Siṅgh, to the throne of Nābhā in 1783 at the age of eight, under the guardianship of his stepmother, Māī Deso, a very resourceful and energetic woman. In 1790, after the death of Māī Deso, he assumed the reins of government into his own hands. Jasvant Siṅgh conducted protracted campaigns, first against Jīnd and then against Paṭiālā, to regain disputed territory for his state. His feud with Jīnd ended in 1789 with the death of the Jīnd chief, Gajpat Siṅgh. With the help of General Perron of the Marāṭhā service; he succeeded in checking the advance of the Irish adventurer, George Thomas. In 1804, he entered into alliance with Lord Lake against Jasvant Rāo Holkar. In 1805, Rājā Jasvant Siṅgh in company with Rājā Bhāg Siṅgh of Jīnd appealed to Mahārājā Raṇjīt Siṅgh to arbitrate his dispute with Paṭiālā and though the dispute was not resolved, Jasvant Siṅgh was able to extend his territory with grants from Raṇjīt Siṅgh. Despite these favours, Jasvant Siṅgh joined hands with the other Sutlej princes under the treaty of 1809. Jasvant Siṅgh helped the British in the Gurkhā war in 1814 as well as in the Kābul campaign in 1838.

         Rājā Jasvant Siṅgh was a popular prince much loved by his subjects. Writing about him, Sir David Ochterlony, British diplomat and soldier, said, "Jaswant Siṅgh is one of the principal Sirdars under our protection and by far superior in manner, management, and understanding to any of them I have yet seen." Sir Lepel Griffin considered him "the nearest approach to the civilized among the whole set of rude barons."

        Rājā Jasvant Siṅgh died at Nābhā on 22 May 1840.