Udham Singh was an Indian revolutionary, best known for assassinating Michael O’Dwyer(popularly known as General Dwyer) on 13 March 1940 in what has been described as an avenging of the Jallianwalla Bagh Massacre. Singh is a prominent figure of the Indian independence struggle. He is sometimes referred to as Shaheed-i-Azam Sardar Udham Singh. A district (Udham Singh Nagar) of Punjab is named after him.

source: http://en.wikipedia.org/wiki/Udham_Singh