The following is the historical account of how Jassa Singh came to be known as Ramgharia by Dr. Teja Singh
Failing in his negotiations with the head of the Khalsa Oal, Adeena Beg turned to the smaller fry. He was able to net in Jassa
Singh of Ichogil, later on called Ramgarhia. This man had been ostracized by the community for the alleged murder of his infant
daughter.2 He went offin a huff, and readily agreed to serve under Adeena Beg.
All the while his conscience smote him for having deserted his brethren, andhe was ever on the lookout for a chance to go back to them. His opportunity came in the siege of RamRauni. Siege ofRam Rauni : After the rainy season when the Sikhs gathered in large numbers to celebrate the Dewali festival at Amritsar, Mir Mannu thought that he could deliver a heavy blow at them He marched with a force on the fort of Ram Rauni, and ordered Adeena Beg to bring up his armies. The Sikhs stood on the defensive, about 500 taking shelter within the enclosure and the rest hiding themselves in the bushes near Ramsar.
Those inside made occasional stories at night, while the others harassed the enemy from outside. The siege went on for about three months, from October to December 1748, and about 200 Sikhs were killed. There was great scarcity of food and fodder, and the besieged were obliged to resort to many shifts to replenish their resources.
Delightful stories are told ofJai Singh Kanhaiya and his mare: how he would jump over the walls and, wresting provisions from the commissariat shops and throwing them in, how he would climb back into the fort. In their extreme distress the besieged decided to rush out and die fighting. Before doing so, they offered a prayer ending in the famous exclamation ofSat Sri Akal!.
This was heard by Jassa Singh, who was in the ranks of Adeena Beg outside. It sent a thrill into his heart, and he could not resist the appeal of the familiar cry. He decided to rejoin his brethren. A message was sent in by him, requesting his comrades in faith to forgive him and to have him
back. They welcomed him with open arms, and he came in with a hundred followers. Just at this time a thing happened which obliged
the Mughals to raise the siege and to leave the Sikhs to themselves.
After the Seige was over Bhai Jassa Singh Came to be known as Jassia Singh Ramgharia after he managed to escape from Ramarauni Fort
Source: Teja Singh’s History of sikhs
Jassa Singh Ramgharia is also credited with bringing the throne of Aurengzeb to Sri Darbar Sahib.