Despite his age and failing health, when the call to fight came, the old lion plunged into the thick of it and for nearly a year battled against the British forces with grim determination and undaunted courage.
In Bihar, Kunwar Singh was the chief organizer of the fight against British. He assumed command of the soldiers who had revolted at Danapur on 5th July. Two days later he occupied Arrah, the district headquarter. Major Vincent Eyre relieved the town on 3rd August, defeated Kunwar Singh's force and destroyed Jagdishpur. Kunwar Singh left his ancestral village and reached Lucknow in December 1857. In March 1858 he occupied Azamgarh. However, he had to leave the place soon. Pursued by Brigadier Douglas, he retreated towards his home in Bihar. On 23 April, Kunwar Singh had a victory near Jagdishpur over the force led by Captain Le Grand, but the following day he died in his village. The mantle of the old chief now fell on his brother Amar Singh who, despite heavy odds, continued the struggle and for a considerable time ran a parallel government in the district of Shahabad. In October 1859 Amar Singh joined the rebel leaders in the Nepal Terai.
The part which Kunwar Singh played in the First War of Independence marks a glorious chapter in the chequered history of his country. After harrying the British at the head of a devoted band of followers for nearly a year Kunwar Singh was forced to retreat to his ancient seat at Jagdishpur. It is believed that while crossing the Ganga on his way to Jagdishpur he was wounded in the arm by the pursuing forces and the old warrior severed the injured limb and flung it into the Ganga as his last offering. Soon after he fought his last battle near Jagdishpur on the 23rd April, 1858 in which the British forces were completely routed. Kunwar Singh passed away the next day.
To honor his memory and his contribution to India’s freedom movement, the Republic of India issued a commemorative stamp on 23rd April, 1966.