Faujdar Thakur Bhajja Singh was a chieftain of Sinsini (Later Bharatpur Kingdom) who led the Jats from AD 1688-98. Thakur Brij Raj Singh and Thakur Bhajja Singh were brothers. Rao Churaman Singh Of Thun was the son of Thakur Brij Raj Singh and Raja Ram Jat ( Raja Ram Sinsinwar) was son of Thakur Bhajja Singh.
After the death of Raja Ram Jat, his old father Thakur Bhajja Singh of Sinsini assumed the leadership of the Jats After the death of Raja Ram his father Bhaja Singh became the leader of Jat confederacy and continued plundering and narrating the Moghuls.
Aurangzeb appointed Rajput Raja of Jaipur Raja Bishan Singh, grandsons of Mirza Raja Sawai Jai Singh, the Governor of Mathura and promised him of Jagir of Sinsini. Raja Bishan Singh was very loyal to the Moghuls and took an oath to destroy the fort of Faujdar Bhaja Singh. Prince Bidar Bakht launched an attack on Sansani. His troops could not advance through the thick undergrowth surrounding the fort. The attack got halted and Bidar Bakht laid siege. It took them four months to close in with the walls of the fort. During this period the royal troops were constantly harassed by Jat rallies particularly against their lines of communication. Finally they managed to place a charge against the gate. The Jats had foreseen this and had buttressed the walls and gates with stones and earth work. The charge exploded out wards and inflicted casualties in the Moghul Army. In 1590, with another effort the wall was breached and ultimately the fort was captured. The Jats in this encounter took a toll of 200 Moghuls and 700 Rajputs. They lost the fort only after fighting to the last man and last round. Bhaja Singh retired to the fortress of Sogaryas. It is said that in 1691 Raja Bishan Singh entered surreptitiously into the fortress of Sogaryas, when its gates were open for supplies and succeeded in capturing and killing Bhaja Singh with his 500 followers, thus keeping his word to his masters, the Moghuls.
Reference –
• U N sharma, jaton ka navin Itihas, I, 342,180
• Qanungo, History of the Jats, Ed Dr Vir Singh,2003, p.26
. The Jats – Their Role in the Mughal Empire/Chapter II, p.41