Sikhism achieved a series of military victories and created a Sikh Empire in 1799. The Sikh empire had its capital in Lahore, spread over almost comprising what is now northwestern Indian subcontinent. The Sikh Empire entered into a treaty with the colonial British powers, with each side recognizing Sutlej River as the line of control and agreeing not to invade the other side. Ranjit Singh's most lasting legacy was the restoration and expansion of the Harmandir Sahib, most revered Gurudwara of the Sikhs, with marble and gold, from which the popular name of the "Golden Temple" is derived. After the death
Dal Khalsa (International) the followers of a Sikh sect known as the Nirankaris (whom other Sikhs regard as heretics). This clash had occurred at a Nirankari event at the Harmandir Sahib in Amritsar on 13 April 1978, in which 3 Nirankaris and 13 Sikhs were killed. At its first annual conference held in Gurdaspur during December, 1979, the Dal Khalsa passed a resolution demanding that Amritsar be officially declared a "holy city". A demand that was supported by other Sikh organisations such as the Sikh Students Federation and one which was later taken up with the Indian government by the SGPC in 1980.