Senior IAS officer Rajiv Gauba on Thursday took charge as the Union Home Secretary.
Gauba, 58, will have a fixed two-year tenure.
He took charge from Rajiv Mehrishi, a 1978 batch Rajasthan cadre IAS officer who superannuated from service on Wednesday.
A 1982 batch officer of the Jharkhand cadre, Gauba joined the Home Ministry on June 27 and has since served as an Officer on Special Duty.
Earlier, Gauba was Secretary in the Urban Development Ministry.
In a major bureaucratic reshuffle, the Appointments Committee of the Union Cabinet headed by Prime Minister Narendra Modi on June 21 cleared Gauba's appointment as Union Home Secretary.
This is Gauba's second stint in the Home Ministry.
Earlier, as Additional Secretary, Gauba looked after the Left Wing Extremism division of the Ministry. He was then appointed the Chief Secretary in his parent cadre of Jharkhand.
"He has wide-ranging experience in senior positions in the central and state governments and in international organisations. Hailing from Punjab, the 1959 born Gauba is a Physics graduate," a Home Ministry statement said.
Gauba has also served in the Ministries of Defence, Environment and Forests and Department of Electronics and Information Technology.
"Gauba also served in the International Monetary Fund representing India for four years on the board of IMF." IANS