Narendra Modi will find out in June if he’s won a record third term in a row as India’s prime minister. After a decade in power he is omnipresent – but frequently seen at his side is a less talked-about politician, who has helped mastermind the extraordinary rise of the Bharatiya Janata Party (BJP).

Amit Shah – often called India’s “second most powerful man” – is a formidable old friend, Mr Modi’s closest confidant and the brains behind his election juggernaut.

By Geeta Pandey

A hardline Hindu nationalist popularly known as Amitbhai, Mr Shah has charted numerous election wins for the BJP. He lacks the star power of the PM and is a more private man. But he is an excellent organiser and campaign strategist, a shrewd politician – and like Mr Modi, a hugely polarising figure.

His supporters view him as the “great defender of the Hindu faith” but those who dare cross him find a feared adversary.

Critics say he is the driving force behind some of India’s most controversial legislation, including scrapping Kashmir’s partial autonomy – which had been a BJP manifesto pledge for decades – and a new citizenship law that has been described as deeply discriminatory towards Muslims.

Speaking to the BBC, friends and colleagues who have known him since his school days and early career – even those who stood by him while he was briefly jailed – provided a rare insight into his early life. They described what they saw as the secret of his extraordinary success, spoke of his deep loyalty and affection for party workers, and appetite for hard work.

This story was originally published in bbc.com. Read the full story here.