Justices A M Khanwilkar, D Y Chandrachud, Ashok Bhushan and L Nageshwar Rao were on Friday sworn in as Supreme Court judges, taking the apex court's strength to 29, including Chief Justice T S Thakur.
They were administered the oath of office by CJI Thakur.
Justices Khanwilkar, Chandrachud and Bhushan were the Chief Justices of Madhya Pradesh high court, Allahabad high court and Kerala high court, respectively.
Justice Rao, who was a senior advocate and former additional solicitor general, has been elevated as an apex court judge from the bar.
The sanctioned strength of judges in the apex court is 31, including the CJI. There is only one woman judge in the Supreme Court,, Justice R Banumathi.
The elevation of the four judges were the first set of recommendations made by the Supreme Court collegium after the National Judicial Appointments Commission Act which sought to scrap the collegium system was struck down by an SC bench in October last year.
The apex court will also see five judges retiring this year, including Justice A R Dave who will retire on November 18, Justice F M I Kalifulla on July 22, Justice V Gopala Gowda on October 5, Justice Shiva Kirti Singh on November 12 and Justice C Nagappan on October 3. The Chief Justice of India will retire on January 3, 2017.
Former Additional Solicitor General L Nageshwar Rao is the fourth member from the bar recommended for Supreme Court judgeship by the collegium after the Narendra Modi government came to power in 2014.
In 2014, U U Lalit and R F Nariman were appointed as SC judges, but the government had returned the file of former Solicitor General Gopal Subramanium citing negative Intelligence Bureau report.
Justice Khanwilkar was appointed as the Chief Justice of the Madhya Pradesh high court on November 24, 2013. Prior to this, he was appointed the Chief Justice of the Himachal Pradesh high court on April 4, 2013.
He became the additional judge of the Bombay high court on March 29, 2000 and permanent judge on April 8, 2002.
Justice Chandrachud was sworn in as the Chief Justice of Allahabad high court on October 31, 2013.
He was designated as senior advocate in 1998 and was the additional solicitor general of India from 1998 to 2000.
Justice Bhushan, a law graduate from Allahabad University in 1979, was enrolled as an advocate with bar council of Uttar Pradesh in 1979.
He was elevated as permanent judge of the Allahabad high court on April 24, 2001 and also served as the chairman of higher judicial service committee.
Before becoming the Chief Justice of Kerala high court on March 26, 2015, he became a judge at the same court on July 10, 2014.
Justice Rao, a senior advocate from Andhra Pradesh, had served three terms as an additional solicitor general and he resigned from his last stint in December 2014.
Rao was enrolled in June 1982 and practised in the Andhra Pradesh high court till January 1995, when he shifted to the apex court.
He was standing counsel for various universities in Andhra Pradesh and had appeared in constitutional and administrative law matters in the apex court and the high courts of Jammu and Kashmir, Punjab and Haryana, Guwahati, Karnataka and Patna.