Final answer:
Nawab Kapur Singh died on 20 June 1761. He was a key figure in the Sikh Confederacy and the founder of the Dal Khalsa. He was instrumental in the foundation of the Dal Khalsa, an organization which played a significant part in the revival of Sikh power in Punjab.
Step-by-step explanation:
Nawab Kapur Singh was a prominent leader in the Sikh Confederacy, known for his role in strengthening and organizing the Sikh military forces during the 18th century. You asked, when did Nawab Kapur Singh die? The correct answer is c. 20 June 1761. He was instrumental in the foundation of the Dal Khalsa, an organization which played a significant part in the revival of Sikh power in Punjab after the tyranny and persecution they faced under the Mughal rule.