Mr Gandhi is the grandson of two legends of India's freedom movement, Mahatma Gandhi and C Rajagopalachari. He is the son of Gandhi's son Devdas Gandhi and Mr Rajagopalachari's daughter Lakshmi.
But even beyond his illustrious credentials, many would see Mr Gandhi as an obvious choice for an opposition aggressively taking on Prime Minister Narendra Modi and the BJP.
When the BJP was voted to power in 2014, the former governor famously wrote a brutally straightforward open letter to PM Modi. "This comes with my hearty felicitations. I mean and say that in utter sincerity, which is not very easy for me to summon, because I am not one of those who wanted to see you reach the high office that you have reached," he wrote.
"A historic win it has been for you, Mr. Modi, for which, once again, congratulations. Let it be followed by a historic innings, which stuns the world by surprises your supporters may not want of you but many more would want to see you unfurl... Requite the applause of your support-base but, equally, redeem the trust of those who have not supported you," he advised, signing off as a "fellow citizen".
Mr Gandhi, a graduate of Delhi's prestigious St Stephen's college, is widely admired as an independent thinker.
He was Governor of West Bengal in 2004-09 and has also served as India's envoy to South Africa, Sri Lanka and Norway.
As governor, he was known to travel incognito to rural areas of West Bengal.
The soft-spoken Mr Gandhi didn't mince words after 14 people were killed in police firing in Nandigram in March, 2007, saying he was "filled with cold horror".
It is ironic that Mr Bhattacharya's CPM was among the parties that pitched for Mr Gandhi as president.
Mr Gandhi is married to Tara Gandhi and the father of two daughters. He is known to be fond of Carnatic and Hindu music.
He is also known for his literary works. He translated Vikram Seth's A Suitable Boy into Hindi, has written a novel on Sri Lanka's Tamil plantation workers and also a play in verse on Dara Shikoh.
With Inputs From PTI