Maharaja Man Singh was the last independent Maharaja of Marwar Kingdom and Jodhpur State. He was appointed as Heir Apparent by his grandfather Vijay Singh on 7 November 1791. However upon Vijay Singhs death, Bhim Singh seized Jodhpur and proclaimed himself as the ruler of Marwar. Man Singh was sent to Jalore for his own safety, where he remained throughout the reign of his cousin, Maharaja Bhim Singh of Marwar. He succeeded on his cousins death on 19 October 1803. In 1804 Man Singh broke the treaty with the British for cooperation and formed an alliance with Yashwantrao Holkar, however Jodhpur was invaded by Sindhia and was forced to break their alliance with Holkar and pay heavy tribute. Opposed by many of his principal nobles throughout his reign, he depended on the support of successive factions. The last of these were the Nath family, the Maharaja's spiritual advisers, who came to control state affairs and turned him into a recluse. Many of the nobles fled to neighbouring principalities, state repression having become entirely vengeful and cold-blooded. Man Singh had wanted to marry Krishna Kumari after his cousin's death. Man Singh after finding it unbearable to see his kingdom get destroyed by the Sindhias and his own corrupt nobles and ministers, entered into treaty relations with the British on 6 January 1818.
In 1806 the combined armies of Jaipur, and Bikanerdeclared war on Marwar in order to install a pretender as the Maharaja of Marwar. However Maharaja Man Singh defeated the combined army so comprehensively that Maharaja Jagat Singh of Jaipur had to pay a sum of Rs. 2,00,000 to secure his safe passage. In honour of Man's victory over Jaipur the Jai Pol, or victory gate was built in the fort in 1808.
Asylum to Nagpur ruler
In 1829 Man Singh gave shelter to Mudhoji II Bhonsle, also known as Appa Saheb, the dethroned ruler of Nagpur against the wishes of British. He refused to hand him over to British in spite of persistent demands by Governor GeneralLord William Bentinck. Appa saheb remained in Jodhpur at Man Mandir till his death in 1840. Man Singh died at Mandore, 4 September 1843.