The change of guard is of utmost significance, given the fact that the grand old party secured a tally of just 44 seats in the 2014 Lok Sabha general elections.
Rahul has been at constant loggerheads with Prime Minister Narendra Modi. He has mocked the government as "suit-boot government", a reference to Modi's monogrammed suit which he wore in the Republic Day meeting with Barack Obama in 2016.
Moreover, he used the "acche din government" jibe (which was Modi's election campaign slogan in the 2014 elections, meaning "good days government") and mentioned that he has "failed the country".
The BJP has often ascribed the Congress newly elected President as the 'Yuvraj' and has lashed out at him for reaping benefits of 'dynasty politics'.
The Gandhi scion even justified the charge of being a dynast saying that the entire nation is running on it and hence, one should not go only after him.
Born in one of the politically influential Nehru-Gandhi family, Rahul entered politics in 2004, by contesting the May 2004 general elections, from his father's former constituency of Amethi in Uttar Pradesh.
The Amethi seat had been held by Sonia until she was transferred to the neighbouring seat of Rae Bareilly.
The Congress had been doing poorly in Uttar Pradesh, holding only 10 of the 80 Lok Sabha seats in the state at that time.
This move generated surprise among political commentators, who had regarded his sister Priyanka Vodra to succeed.
Rahul, recently attacked Prime Minister Modi over his claims of growing friendship between India and the United States.
Rahul did not even hold back his opinion on Amit Shah's son, Jay, matter either.
"Amazing transition from Beti Bachao to Beta Bachao," he tweeted.
Adding to this are the Congress president's constant rebuttals with Union Minister Smriti Irani over a plethora of subjects.
To the most recent event Rahul's visit to the temple during election campaigning in Gujarat drew a lot of criticism from the Opposition raising question on his political identity.
He was even accused for politicising religion.
Prime Minister Modi mocked Rahul recently in a Twitter post over his mathematical calculations, when the latter said that prices of foodgrains have risen since BJP took over. Both of them have constantly been in war of words over social media or addressing rallies in the just concluded Gujarat and Himachal Pradesh elections.
The exit polls of Himachal and Gujarat election are heavily in BJP's favour. However, Rahul has consistently denied that he 'doesn't believe in such things' and said that the reality would be out on December 18.
Not so long ago, Rahul was criticised, rather bullied, for not having the knack of wooing people with words, something the other leaders of his party, and other parties, have mastered over the time.
But in a surprising social media overdrive, the Gandhi scion has been, of late, putting out well-aimed tweets, consisting primarily of couplets, and life lessons.
In his first interview with foreign media in 2004, Gandhi portrayed himself as a uniter of the country and condemned divisive politics in India, saying that he would try to reduce caste and religious tensions.
The 2004 elections marked the return of Congress back at the Centre. The introduction of Rahul and Priyanka to politics, further strengthened the grand old party. This was the revival the Congress needed.
Rahul has been credited by many Congress leaders of bringing in unity and ushering in youth to re-energize the party cadre.
He has been instrumental in helping his party to win elections in Himachal Pradesh, Karnataka and Uttarakhand to name a few, that was ruled by the BJP earlier.
A supporter of women empowerment, Rahul backed the Women's Reservation Bill, which would allow 33 percent reservation of all the Lok Sabha and state legislative assembly seats for women. He has also backed the repeal of Section 377 of the Indian Penal Code and the decriminalisation of homosexuality.
He was elected the General-Secretary of Indian Youth Congress in 2007. Subsequently, he was appointed the Vice-President of the Congress in 2013.
In the 2009 general elections, Rahul undertook a countrywide political tour, addressing rallies and also taking part in a 'padayatra' to connect with the people better.
He has been credited with the grand old party's revival in Uttar Pradesh, where they won 21 out of the total 80 Lok Sabha seats.
The Congress-led United Progressive Alliance (UPA) won the elections comprehensively.
In May 2011, Rahul was arrested by the Uttar Pradesh Police at Bhatta Parsaul village after he turned out in support of agitating farmers, demanding more compensation for their land being acquired for a highway project.
He blamed the then Chief Minister of Uttar Pradesh, Mayawati for not allowing him to protest and to address the farmers' needs.
However, Rahul has faced a lot of controversies. During a rally in Allahabad in 2013, he said that: "Poverty is just a state of mind. It does not mean the scarcity of food, money or material things. If one possesses self-confidence, then one can overcome poverty." The phrase "state of mind" drew sharp criticism from the opposition. BJP Uttar Pradesh spokesperson Vijay Bahadur Pathak criticised his comment and said that he was 'mocking the poor'.
Once, he also said that the introduction of Jan Lokpal Bill in the country would not be able to root out corruption alone. Anti-corruption leader Anna Hazare slammed him and said that he had made the bill "weak and ineffective".
After the 2013 Muzaffarnagar riots, Rahul claimed that a police officer had told him that Pakistan's Inter Service Intelligence (ISI) was trying to recruit disgruntled riot-affected youngsters, at an election rally in Indore. However, the district administration, the Uttar Pradesh government, the Union Home Ministry, the Research and Analysis Wing (RAW) and the Intelligence Bureau (IB) denied any such development.
This remark drew heavy criticism from various political outfits such as BJP, SP, CPI (Communist Party of India) and Janata Dal (United) (JD(U)). Congress leader Jairam Ramesh also demanded him to apologise to the Muslim community for the comment.
After the Gujarat elections this year, senior Congress leader Ghulam Nabi Azad had said "The entire country has lots of expectations from Rahul Gandhi. Much before he was elected, he has shown his mettle. He knows his responsibility."
Rahul's take over comes with a huge responsibility as the party was dethroned from many states, including Assam, Uttarakhand, Manipur and Maharashtra.
Karnataka, which goes to polls early next year, would be his first litmus test.