The temple had been occupied by a group of Sikh separatists following Jarnail Singh Bhindranwale. The Indian Prime Minister Indira Gandhi ordered the temple to be cleared after attempts at negotiation failed. The occupiers refused to depart peacefully and a firefight ensued - with 83 soldiers and 493 occupiers killed, and many more injured.
It was considered by some Sikhs as a great insult because of the use of force at their holy place. The later assassination of Indira Gandhi by her Sikh bodyguards was said to be in response.