Mr Rahul Gandhi was named president of India's opposition Congress party yesterday, taking over the 132-year-old party from his mother.
The Italian-born Mrs Sonia Gandhi, 71, was Congress president for nearly two decades.
Celebrations broke out after the announcement, with party workers and supporters setting off fire crackers and dancing outside the headquarters in New Delhi.
Mr Gandhi, 47, himself was on the campaign trail in Gujarat state when the announcement was made.
"This is a historic occasion," said Congress leader Mullappally Ramachandran, who made the announcement at a press conference here.
Mr Gandhi comes from the Gandhi-Nehru dynasty, considered political royalty in India, which has given the country three prime ministers - his great-grandfather Jawaharlal Nehru, grandmother Indira Gandhi and father Rajiv Gandhi.
The Gandhi scion, who is the 60th president, takes over at a time when the party has still not completely recovered from a humiliating defeat in the 2014 election in which it won just 44 out of 543 seats in the Indian Parliament.
The first challenge for him is to build up his party and build it up organisationally. He has to clarify its economic vision.
MR AMULYA GANGULI, a Delhi-based political analyst, on Mr Rahul Gandhi.
The party has also faced electoral reversals in subsequent state elections including in Delhi.
Analysts say Mr Gandhi, who has been in a leadership position since 2013 as vice-president, has multiple challenges before him.
"The first challenge for him is to build up his party and build it up organisationally. He has to clarify its economic vision," said Delhi-based political analyst Amulya Ganguli.
"But it is a good time for him to take over. The Congress has a good shot of winning state elections next year in Chattisgarh, Madhya Pradesh, Rajasthan and Karnataka.
"Mr Gandhi has made a mark in Gujarat. He is no longer the adolescent part-time politician," Mr Ganguli added.
Mr Gandhi, who entered politics 13 years ago and for years shunned any leadership role, is now expected to choose his own team and put forward his vision for the party, which traditionally has been rooted in socialism and has its support base among the poor.
He will also need to ensure that the party's traditional vote bank in rural India, like farmers, remains intact amid efforts by Prime Minister Narendra Modi's Bharatiya Janata Party to woo these same voters.
Some allies remain positive that Mr Gandhi will rise to the occasion.
"Whether the Congress wins or loses in Gujarat, it is a turning point for Rahul Gandhi because he has gained credibility during the Gujarat elections. Allies are looking to him now. He is the only alternative to Modi because Congress is the only alternative to the BJP," said Mr Sudhir Panwar a senior leader from the Samajwadi Party in the state of Uttar Pradesh.
In Gujarat, Mr Gandhi has been the face of the Congress campaign.
He has successfully forged an alliance with Mr Hardik Patel, a leader of the powerful Patel community, and also undertaken a tour of temples in the state as part of a strategy to win Hindu votes.