[1] During his army career, he had commanded the Operation Blue Star under orders from Indira Gandhi to clear the Golden Temple shrine.

As the Chief of the Army Staff, he planned and executed Operation Brasstacks, a major military exercise, along the Rajasthan border.

Sundarji was born in a Tamil Hindu Brahmin family in Chengelpet, Madras Presidency, British India on 28 April 1928.

[1] His early career as an army officer involved operating in the troublesome areas of the North-West Frontier Province and then in Jammu and Kashmir.

He played an important role as brigadier general staff of a corps in the Rangpur sector of Bangladesh, during the Indo-Pakistani War of 1971.

He was chosen by General K. V. Krishna Rao to be part of a small team for reorganising the Indian Army, especially with regard to technology.

[6] In 1984, he led Operation Blue Star, intended to evict extremists who had occupied the Golden Temple in Amritsar.

The Chinese had occupied Sumdorong Chu, and Sundarji used the Indian Air Force's new airlift capability to land a brigade in Zimithang, north of Tawang.

Indian forces took up positions on the Hathung La ridge, across the Namka Chu river, where India had faced a humiliating defeat in 1962.

Western diplomats predicted war, and some of Prime Minister Rajiv Gandhi's advisers blamed Sundarji's recklessness.

But Sundarji stood by his steps, at one point telling a senior aide, "Please make alternate arrangements if you think you are not getting adequate professional advice."

He was also involved in Operation Brasstacks, a large-scale mechanised artillery and war gaming effort in July 1986 near the Pakistan border, which led to similar Pakistani buildup.

His second wife, Vani, wrote the introductory chapter of Sundarji's memoirs Of some consequence – A soldier remembers, which was published after his death.