Colonel Reginald Edward Harry Dyer, CB (9 October 1864 – 23 July 1927) was an Indian-born officer of the Bengal Army and later the newly constituted Indian Army.
His military career began serving briefly in the regular British Army before transferring to serve with the Presidency armies of India.
As a temporary brigadier-general he was responsible for the Jallianwala Bagh massacre in Amritsar (in the province of Punjab).
He has been called "the Butcher of Amritsar", because of his order to fire repeatedly on a crowd of peaceful protestors.
This resulted in the killing of at least 379 people and the injuring of over a thousand more.Subsequently Dyer was removed from duty and widely condemned both in Britain and India, but he became a celebrated hero among some with connections to the British Raj.
Some historians argue the episode was a decisive step towards the end of British rule in India.