One of the Nankana Sahib martyrs, was the leader of the jatha of more than one hundred Sikhs who were attacked in Gurdwara Janam Asthan (birthplace of Guru Nanak) by the custodian of the shrine, Mahant Narain Das, and his accomplices, and killed to a man.

Lachhman Singh was born to Mehar Singh and Har Kaur in 1885 at the village of Dharovali, in Gurdaspur district of the Punjab. Mehar Singh, who retired as a police inspector in 1888, had been awarded for his meritorious record six squares of land in Chakk No. 33 in canal colony in Sheikhupura district. Four years later, he shifted his family of four sons and a daughter to this village, which began to be called Dharovali after their original village. Lachhman Singh passed his boyhood herding cattle and learning to read Gurmukhi and recite gurbani. In 1901, he was married to Indar Kaur, daughter of Buddh Singh Bundala of Chakk No. 64. In 1910, he joined Khalsa Parcharak Vidyala, a missionary school at Tarn Taran, and returned after two years training to devote himself to the cause of education and to spreading Sikhism in the canal colonies.

He started a girls primary school and a Khalsa orphange in his village with donations collected from the farmers. Reports about the corruption and licentiousness of Mahant Narain Das, who was in control of the principal sacred shrine, Gurdwara Janam Asthan, at Nankana Sahib, led Lachhman Singh to call a public convention in his village, Dharovali, on 1-3 October 1920. The Shiromani Gurdwara Parbandhak Committee, which was formed at Amritsar on 15 November 1920, also decided to convene a conference at Nankana Sahib on 4-6 March 1921 with a view to exerting pressure on the Mahant to reform himself and make over control of the gurdwara to a democratically elected body. Lachhman Singh learnt about the conspiracies Mahant Narain Das was hatching against the reformers. He and Kartar Singh Jhabbar, another equally dashing leader of the Bar Khalsa Diwan, decided on 17 February 1921 that they would proceed to Gurdwara Janam Asthan and claim possession of the shrine on behalf of the Panth.

The date fixed was 20 February when the Mahant, according to their information, was scheduled to attend a Sanatan Sikh conference at Lahore. Lachhman Singh was to march with his jatha from Dharovali through the darkness of the night of 19 February and Kartar Singh Jhabbar from Sachcha Sauda was to join him with his comrades at dawn at Chandarkot canal waterfall bridge, about 8 km north of
Nankana Sahib. They sent a special messenger to Amritsar to secure the concurrence of the Shiromani Gurdwara Parbandhak Committee.
The Committee did not agree and deputed Dalip Singh of Sahoval to go and dissuade Lachhman Singh and Kartar Singh Jhabbar from taking any precipitate action. Dalip Singh succeeded in contacting Kartar Singh Jhabbar and bringing him round to the viewpoint of the Shiromani Gurdwara Parbandhak Committee. Then they drafted a hukamnama, signed by six prominent leaders including Kartar Singh Jhabbar, to be delivered to Jathedar Lachhman Singh to stop him from proceeding to Nankana Sahib.

Lachhman Singh had meanwhile left Dharovali along with his comrades. They offered the ardas and prayed for the success of their mission. Volunteers from villages en route increased their number to more than 130. Taking a short cut, they went by the village of Mohlan and not by Chandarkot bridge, 3 km south, which was the rendezvous fixed for a meeting with Kartar Singh Jhabbar. Dalip Singh who was carrying the hukamnama combed the area round Chandarkot till the small hours of 20 February but failed to locate Lachhman Singh's jatha.

Exhausted by his fruitless wandering, he retired for rest to Uttam Sirrgh's factory, about a mile away from Gurdwara Janam Asthan leaving his companion, Waryam Singh, to continue the search. The latter did meet Lachhman Singh and delivered to him the message commanding him to halt and go back with the jatha. The jatha was bound by the ardas it had offered before setting out on its march. So Lachhman Singh refused to comply and entered, along with his companions, Gurdwara janam Asthan at 5.45 a.m. chanting hymns.

All of a sudden bullets began flying in from the southwest corner of the roof of the Mahimankhana or guest house of Mahant Narain Das. Those squatting in the compound below were killed in the shooting. The Mahant's men then descended and pounced upon their prey with swords, hatchets and other lethal weapons and made short work of the devotees. A bullet-hole was made in the silver-plated door of Chaukhandi, the sanctum-sanctorum, where Lachhman Singh sat in attendance behind the Guru Granth Sahib. His companions stood in front in a row to protect the Holy Book from desecration. All of them including Lachhman Singh fell to the bullets fired by the Mahant's men who had broken open the door. This happened on 20 February 1921.

Source: Encyclopaedia of Sikhism, Harbans Singh