Lachman Dev was born in 1670 at Rajouri in the Jammu hills, became a bairagi ascetic named Madho Das, and had a dera on the Godavari at Nanded. Guru Gobind Singh Ji came there in 1708. The account of the exchange is short: the Guru asked who he was and he answered that he was the Guru's banda, his slave.
He was given five arrows, a nishan, a drum, a council of five Sikhs and instructions, and sent north. Within two years he had taken Samana, Sadhaura, Kapuri and then Sirhind. At Chappar Chiri on 12 May 1710 he defeated and killed Wazir Khan, who had ordered the bricking up of the younger Sahibzade. Sirhind was destroyed.
He struck coin in the name of the Gurus and issued orders under a seal that named Nanak and Gobind Singh. He abolished the zamindari system in the territory he held and gave the land to those who worked it. That is the first such measure in the region by two centuries.
He was besieged at Gurdas Nangal near Gurdaspur for eight months in 1715. The garrison ate bark and boiled leather. He was taken with several hundred men, paraded to Delhi in a cage, and executed in 1716 after his young son was killed in front of him.
His measures on land were reversed. His coinage survives in collections. Fatehgarh Sahib and Chappar Chiri hold memorials to him, the latter built in 2011.
The force he raised came largely from the Malwa peasantry and from communities the revenue system had pressed hardest, which is why the land measure came when it did and why it held for as long as he did.
He appointed his own thanedars and faujdars and issued orders over a tract running from the Sutlej toward the Jamuna. It was an administration rather than a raid, which is what made it worth destroying.
He was captured at Gurdas Nangal in 1715 and executed at Delhi in 1716 with several hundred of his men. The state lasted six years.