Reign of son Chand Kaur:

After the death of Ranjit Singh on 27 June 1839, Kharak Singh was appointed as his successor and Raja Dhian Singh Dogra as his wazir (vizier). The new Maharaja only ruled for a few months until October 1839, when he was overthrown in a coup by his son, Nau Nihal Singh, and Dhian Singh. He was imprisoned at Lahore until his death in November 1840 from slow poisoning. Contemporary chroniclers suggest that the poison had been administered under Dhiān Siṅgh's orders.

Returning from the cremation of his father on 5 November, Nau Nihal Singh went through the gate of the Hazuri Bagh with his companion Udam Singh, son of Gulab Singh, and Dhian Singh's nephew. As they passed through the gate stones fell from above, killing Udam Singh and injuring the prince. Dhian Singh, who was a few steps behind, immediately arranged for the prince to be taken into the fort. Nobody else was allowed into the fort, not even his mother, Chand Kaur, who beat on the fort gates with her bare hands in a fever of anxiety. Eyewitnesses stated that before he was taken into the fort the prince appeared to be only slightly injured, was conscious and asked for water. However, when his mother and friends were allowed in to see him, he was dead with severe injuries to his head.