One of the prominent military leaders of the Sikhs in the second half of the eighteenth century, was born in 1723 at Ichogill, a village 20 km east of Lahore. His grandfather, Hardas Singh (D. 1716) had received pahul, the vows of the Khalsa, at the hands of Guru Gobind Singh and had fought in the campaigns of Banda Singh Bahadur. His father, Bhagvan Singh was killed in a fight against Nadir Shah during his invasion of India in 1739. Young Jassa Singh then joined the jatha of Nand Singh Sahghania and learnt the art of warfare at an early age.

In 1745, he was deputed to settle terms with Adina Beg, the faujdar of the Jalandhar Doab, who was harassing the Sikhs under instructions from Nawab Zakariya Khan, the Mughal governor of Lahore. The wily faujdar, Adina Beg, prevailed upon Jassa Singh to accept office under hint, with a minor command of a regiment consisting of 100 Sikhs and 60 Hindus. The Sikhs were greatly annoyed at the conduct of their envoy, but Jassa Singh did not remain with Adina Beg for long. When in October 1748, the Sikhs gathered at Amritsar to celebrate the festival of Divali, Mir Mannu, the new provincial governor, marched upon the city to expel the Sikhs. The Sikhs disappeared into the neighbouring jungle, but 500 of them took shelter within their newly built fortress, Ram Rauni, and defied the Mughal force. The mud-fortress was besieged and skirmishes continued for four months in which two hundred Sikhs lost their lives. The survivors requested Jassa Singh to come to their rescue.

Jassa Singh left Adina Beg, and made an appeal to Kaura Mall, the Diwan of Lahore and a Sahajdhari Sikh, to save the Sikhs from destruction. At the Diwan's intercession, Mir Manna raised the siege, though the fortress of Ram Rauni was completely destroyed.
Mir Manna's death in November 1753 plunged the Punjab into anarchy. The Sikhs again emerged into the open and decided to rebuild the Ram Rauni fort. Jassa Singh was assigned to this task and he, with the help of his contingent, reconstructed the fortress and named it Ramgarh. Since then Jassa Singh, earlier known as Ichogillia after the name of his village, or thoka (carpenter, the caste he carne from) began to be called Ramgarhia in appreciation of the work done by him.

In April 1758, Adina Beg became governor of the Punjab. He sent a strong force under Mir 'Aziz Bakhshi to clear the forests in which Sikhs had taken shelter. A large number of them including Jassa Singh Ramgarhia, Jai Singh Kanhaiya and Amar Singh Kingra, fled to Amritsar and took shelter in the fortress. Ramgarh was besieged. Jassa Single and Jai Singh made numerous sallies killing a large number of the besiegers, but were ultimately forced to evacuate.

After Adina Beg's death in September 1758, the roving bands of the Sikhs returned. Jassa Singh Ramgarhia and Jai Singh Kanhaiya united and within a short time they seized large slices of territory in four out of the five Doabs; they occupied the fertile tract called Riarki to the north of Amritsar embracing the district of Gurdaspur.

Within a decade Jassa Singh became one of the leading fig-ures of the Dal Khalsa. In 1770, he led plundering expeditions into the hills. The local rajas sought safety in submission and Jassa Singh collected a tribute of 200,000 rupees from the Kangra states. He built a fort at Talvara on the left bank of the Beds and stationed his brother, Mali Singh, with 4,000 horse, in the fort. Jassa Singh Ramgarhia along with other Sikh sardars, fought many a pitched battle against the Afghan invader, Ahmad Shah Durrani.

As the Afghan threat receded, the Sikh sardars began fighting among themselves. The Ramgarhia-Kanhaiya cleavage over their adjoining territories in the districts of Gurdaspur and Hoshiarpur widened. In the battle of Dinanagar in 1775, Jassa Singh Ramgarhia joined the Bhangi sardars against the forces of the Kanhaiyas and the Sukkarchakkias. Soon a rift appeared betweenJassa Singh Ramgarhia and Jassa Singh Ahluvalid when the latter wrested Zahura, a Ramgarhia territory, and conferred it upon Baghel Singh KarorSinghia. Jassa Singh Ramgarhia and Jassa Singh Ahluvalia became sworn enemies of each other. Jai Singh Kanhaiya joined Jassa Singh Ahluvalia and the Ramgarhia Sardar had to flee the Punjab.

Driven out of the Punjab, Jassa Singh became a soldier of fortune. He took possession of Hissar and raised a large body of irregular horse, his depredations extending to the gates of Delhi and its suburbs and into the Gangetic Doab. Jassa Singh and other Sikh chiefs conquered Delhi and entered the Red Fort. Jassa Singh Ahluvalia ascended the throne on 11 March 1783, but Jassd Singh Rdmgarhia challenged his right to do so at which the Ahluvalia chief vacated the royal seat. Jassa Singh Ramgarhia then invaded Meerut and levied an annual tribute of 10,000 rupees on the Nawab. Soon a body of 30,000 horse and foot under him and Karam Singh crossed into Saharanpur district, ravaging it freely.

After the death of Jassa Singh Ahluvalia in October 1783, there were further fissures in the Dal Khalsa. Jai Singh Kanhaiya and Mahan Singh Sukkarchakkia fell out. Mahan Singh won over to his side Raja Sansar Chand of Kangra and invited Jassa Singh Rdmgarhia to come back to the Punjab and make a bid to recover his lost possessions. Jassa Singh Ramgarhia returned to the Punjab and allied himself with the Sukkarchakkias in order to destroy his old foe, Jai Singh Kanhaiya. Together they marched upon the Kanhaiya citadel of Batala in 1787. Jai Singh was defeated and his son Gurbakhsh Singh killed. Jassa Singh recovered all his lost territories and set himself up at Batala, which he fortified by a thick wall.

At the height of his power, Jassd Singh's territory in the Bari Doab included Batala, Kaldnaur, Dinanagar, Sri Hargobindpur, Shahpur Kandi, Gurdaspur, Qadian, Ghuman, Matteval, and in the Jalandhar Doab, Urmur Tanda, Sarih, Miani, Garhdivala and Zahura. In the hills Kangra, Nurpur, Mandi and Chamba paid him a tribute of two lakh of rupees.
Jassa Singh died on 20 April 1803 at the age of 80.

Source: Encyclopaedia of Sikhism, Harbans Singh