LĀL SIṄGH, BHĀĪ, ruler of the Sikh state of Kaithal, was the younger son of Bhāī Desū Siṅgh, founder of the principality. Unlike other rulers of the cis-Sutlej states, the Kaithal chiefs did not assume the title of rājah (king), but preferred to use the family epithet of Bhāī (lit.brother). Bhāī Desū Siṅgh, who fell out with Rājā Amar Siṅgh of Paṭiālā in 1778, sought the patronage of the Delhi Wazīr, Nawāb Majd ud-Daulah 'Abd ul-Ahad. The latter claimed from him arrears in payment of revenue plus a fine of four lakh rupees. Of this amount Desū Siṅgh arranged to pay three lakh rupees and in lieu of the balance payable he left his son, Lāl Siṅgh, as a hostage. As the balance was not forthcoming soon enough, Lāl Siṅgh was tortured. This embittered him and he became a rebel against his father, who on his release from Delhi interned him at Kaithal. When Desū Siṅgh died in 1781, Lāl Siṅgh was still in confinement. His elder brother Bahāl Siṅgh did all he could to keep him in prison, but Lāl Siṅgh contrived to escape, killed Bahāl Siṅgh and took possession of all the estates of his father. He was a politically shrewd person and could clearly see where his advantage lay. He had great influence with Rājā Bhāg Siṅgh of Jīnd; he befriended the powerful Dīwān Nānū Mall of Paṭiālā, and in the family dispute in the ruling family there he supported Rāṇī Ās Kaur against the weak-minded Rājā Sāhib Siṅgh. This strategy enabled him to retain possession of a few villages in distant districts of Fatehābād and Sirsā. He responded to the call of Bābā Sāhib Siṅgh Bedī for a religious war against the Afghāns of Rāikoṭ in 1798 and grabbed Rāi Ilyās' fort of Wākhā and its surrounding territory. He joined hands with the Marāṭhās to wipe out the British adventurer, George Thomas, in 1802, but was astute enough to perceive the rising influence of the British and, along with Rājā Bhāg Siṅgh, joined hands with them on 15 September 1803, preventing the Marāṭhās from making further inroads. According to Sir Lepel Griffin, "Lal Singh was, at the time of the British advance northwards, in 1809, the most powerful cis-Sutlej chief, after the Raja of Patiala." In 1819, Bhāī Karam Siṅgh son of Bhāī Dhannā Siṅgh and first cousin of Bhāī Lāl Siṅgh, died. Both his widow, Māī Bhāgbharī, and Bhāī Lāl Siṅgh made claims to his estates. The British government, however, allowed the latter to succeed to the estates with a small maintenance grant to the widow.

        Bhāī Lāl Siṅgh died at Kaithal soon after.