(Hindu nationalist Narendra Modi addresses his supporters during a rally ahead of the general election in Itanagar in the northeastern Indian state of Arunachal Pradesh March 31, 2014. REUTERS/Stringer)

Narendra Modi spent his childhood in a modest three-room dwelling made of mud and brick nestled in a narrow, crowded lane in the western Indian town of Vadnagar.

The tea stall his father ran with the help of his sons is just as it was then, a small shed of patched blue-grey tin on the platform of the ramshackle railway station nearby.

Fast forward nearly 60 years and Modi stands on the cusp of leading the world’s biggest democracy, after an election beginning on Monday that looks set to make his Bharatiya Janata Party (BJP) the country’s biggest.

Family members, friends and ordinary people interviewed by Reuters in Modi’s native state of Gujarat put his remarkable journey down to single-minded ambition, an eye for opponents’ weaknesses and his grasp of economic management.