Ranjit Nagara, lit. the drum of victory in battlefield, was the name given the kettledrum installed by Guru Gobind Singh Ji at Anandpur Sahib in 1684.
Nagara, Punjabi for the Persian naqqarah meaning a kettledrum, was a symbol of royalty. As well as fulfilling his spiritual office, Guru Gobind Singh Ji had, like his grandfather, Guru Hargobind Sahib Ji, adopted the emblems of worldly dignity. He wore an aigrette and arms, sat under canopy and went out riding in state. Adding another sign of authority, in 1684, his diwan, Nand Chand, had a kettledrum installed at his bidding.
The massive drum with a metallic hemispheric body was called by Guru Gobind Singh Ji 'Ranjit Nagara'. According to Kuer Singh, Gurbilas Patshahi 10, the masands became afraid lest the beating of the drum should arouse the envy of the local chieftain, and begged the Guru's mother, Mata Gujari Ji, to plead with him not to offend the raja. Guru Gobind Singh Ji, as says Bhai Santokh Singh, Sri Gur Pratap Suraj Granth, spoke to his mother, "Why should anyone resort to antagonism? I am not going to seize anyone's territory."
Ranjit Nagara was usually beaten when Guru Gobind Singh Ji went out for the chase. The thunderous roll of Ranjit Nagara made Raja Bhim Chand, Raja of Kahlur, who was already jealous of the growing influence of Guru Gobind Singh Ji, panicky. He and later his son, Ajmer Chand, supported by other hill monarchs, attacked Anandpur and continued hostilities until Guru Gobind Singh Ji, under pressure of a prolonged siege, was forced to evacuate the fort in December 1705. History provides no clue, but in all probability Ranjit Nagara was left behind in Anandpur.
However, kettledrum as such had become part of Sikh tradition, and it continues to be so till today. Almost every gurdwara now maintains a large kettledrum called dhaunsa or nagara, which is beaten during ardas, the supplicatory prayer, to punctuate certain lines and as a call for meals in the Guru ka Langar.