In 1765, he along with Lahina Singh, adopted son of Gurbakhsh Singh, and Sobha Singh, an associate of Jai Singh Kanhaiya, captured Lahore, from the Afghans. As Lahina Singh was senior in relationship, being his maternal uncle, Gu[jar Singh allowed Lahina Singh to take possession of the city and the fort, himself occupying eastern part of the city, then a jungle. Gujjar Singh erected a mud fortress and invited people to settle there. He sank wells to supply water. A mosque was built for Muslims. The area, the site of present day railway station of Lahore, still bears his name and is known as Qila Gujjar Singh.
Gujjar Singh next captured Eminabad, Wazriabad, Sodhra and about 150 villages in Gujrariwala district. He then took Gujrat from Sultan Muqarrab Khan whom he defeated under the walls of the city in December 1765, capturing both the city and the adjoining country, and making Gujrat his headquarters. Next year, he overran Jammu, seized Islamgarh, Purichh, Dcv Batala and extended his territory as far as the Bhimbar hills in the north and the Majha country in the south. During Ahmad Shah Durrani`s eighth invasion, Gujjar Singh along with other Sikh sarddrs offered him strong opposition.
When in January 1767, tlie Durrani commanderin chief Jahan Khan reached Amritsar at the head of 15,000 troops, the Sikh sarddrs routed the Afghan horde. Soon afterwards Gujjar Singh laid siege to the famous fort of Rohtas, held by the Gakkhars, with the assistance of Charhat Singh Sukkarchakkia, who was on the most amicable terms with him and who gave his daughter, Raj Kaur, in marraige to his son, Sahib Singh. Gujjar Singh subjugated the warlike tribes in the northwestern Punjab and occupied portions of Pothohar, Rawalpindi and Hasan Abdal. Gujjar Singh died at Lahore in 1788.
References :
1. Seetal, Sohan Singh, The Sikh Misals and the Punjab. Ludhiana, n.d.
2. Gupla, Hari Ram, HistoiJ of the Sikhs, vol. II. Delhi, 1978
3. Khushwant Singh, A Hisl.ofy of the Siklis, vol.1. Princcton, 1963
4. Griffin, Lepel, and C.F. Massy, Chiefs and Families of Note in the Punjab. Lahore, 1909