An Indian political revolutionary and a member of the Hindustan Socialist Republican Association, Thapar was executed for his involvement in the 1928 Lahore Conspiracy, which led to the assassination of police deputy J. P. Saunders.
While teaching at India's National College, Lahore, he became one of the founders of a youth independence movement known as Naujawan Bharat Sabha.
After his death, his statue was erected to commemorate his acts of bravery.
He was born and raised in Ludhiana, Punjab, which was then part of British-ruled India.
He and fellow revolutionary Bhagat Singh were both hanged for their roles in the Lahore Conspiracy.