Senior Supreme Court lawyer PP Rao died after suffering a cardiac arrest in New Delhi on Wednesday. He was 84.

Rao, who was considered one of the foremost constitutional law experts in the country, had helped develop the argument against the legal challenge to President’s Rule in four Bharatiya Janata Party-ruled states – Uttar Pradesh, Madhya Pradesh, Rajasthan and Himachal Pradesh – after the Babri Masjid was demolished in 1992. He had successfully argued that a violation of secular ideals of the Constitution was reason enough to dismiss a government.

Born on July 1, 1933, Rao studied at Hyderabad’s Osmania University. He began his career with teaching law at Delhi University in 1961. In 1967, he was enrolled as an advocate by the Bar Council of Delhi, and began practicing in the Supreme Court, according to Bar & Bench.

He was elected the president of the Supreme Court Bar Association in 1991, and was awarded the Padma Bhushan in 2006.