There are many places you might visit to see the changes brought by India’s new era of globalisation, from the software parks of Bangalore, where Vijay Mallya also based his businesses, to the banks and stock markets of Mumbai. But few offered sights as dramatic as the long, jagged coastline of Gujarat, the state that juts out sharply from the country’s western flank. Bordering Pakistan on one side, its proximity to the Persian Gulf had long provided a natural landing point for merchants and migrants. Zoroastrian refugees arrived here from Iran as early as the seventh century, forming what became the Parsi community, one of the India’s more commercially successful minorities. In 1608, in the southern coastal town of Surat, the East India Company established its first ‘factory’, a trading post of fortified warehouses packed with silk, indigo and saltpetre, waiting for galleons to carry it back to Britain. More modern factories, in what had since become a bustling city, now imported, cut, polished and re-exported almost all of the world’s diamonds. In the meantime the surrounding region had once again become India’s gateway for global commerce, and host to some of the grandest endeavours of its tycoon class.

It was here at Jamnagar, just over the waters of the Gulf of Kutch, that Mukesh Ambani’s Reliance Industries built its gigantic petrochemicals and refining complex, by some measures the largest of its type in the world. Another refinery stood just next door, built by the billionaire Ruia brothers of Essar, while the Jindals, another storied business dynasty, ran power plants and steel mills further south. The Gujarati coast was dotted with facilities to welcome container ships, oil tankers and liquefied natural gas carriers. More than anyone, however, commerce in the state had come to be associated with the extraordinary rise of one man: Gautam Adani, perhaps the most aggressive of India’s new generation of tycoons.

I had squeezed into the plush leather seats of one of Adani’s private jets earlier that morning in mid-2013, ready to visit Mundra, an isolated coastal town about 350 kilometres to the west of Ahmedabad, the commercial capital. The surrounding area was little more than scrub-land before Adani, at the time merely an ambitious local businessman, got his hands on it about a decade earlier. Now it was the crown jewel of his business operations, including India’s largest private port, a giant coal-fired power station and a sprawling special economic zone spread out over more than 30 square miles. Reaching the port took eight bumpy hours by road, the pilot told me, looking over his shoulder and yelling over the noise of the engines. In the twin-engine eight-seater we touched down in less than one.

Adani’s own background was modest. A college drop-out from a middle-class family of textile merchants, he began his career in Mumbai’s diamond markets, before returning home to Gujarat to work in a small plastics factory, run by one of his brothers. Eventually he set up his own commodities trading business. Then, expanding at a pace that often looked reckless, he launched successive new ventures spanning ports, infrastructure, power, mining and property. At the start he was a minor figure, unknown outside his home state. But fuelled by quantities of debt that easily outstripped those built up even by adventurous tycoons like Vijay Mallya, Adani became one of India’s most successful self-made industrialists in less than ten years.

The pace and scale of Adani’s expansion was comparable with those of industrial giants of earlier eras. Unable to rely on India’s ramshackle infrastructure, he built his own private railways and power lines. Lacking easy access to domestic coal, he bought mines in Indonesia and Australia, and took their contents back home through his port. In the process he built ‘a vertically integrated global supply chain reminiscent of when Henry Ford once owned Brazilian rubber plantations to supply his car factories’, as the New York Times put it. More to the point, his was an expansion that closely mirrored India’s own.

As the country enjoyed its fastest ever growth in the mid-2000s, so Adani undertook one of its most extravagant investment sprees. In 2002, Adani Enterprises, his main holding company, was worth barely $70 million. A decade later he claimed to have built assets worth $20 billion, while the value of his companies had jumped more than one hundredfold. By the time of India’s most recent election in 2014, Forbes listed his fortune at $7 billion.

Above all, Adani’s controversial reputation rested on a final factor: his friendly ties to Narendra Modi, the man who would go on to become India’s prime minister. Adani’s businesses began taking off in the years following Modi’s arrival as Gujarat’s chief minister back in 2001. Under Modi the state grew into a vibrant industrial hub, with a particular strength in export-focused manufacturing, even being compared with the Pearl River Delta, the region around Hong Kong that powered China’s transformation into a global trading giant.

The two men enjoyed symbiotic careers. Modi’s pro-business policies helped Adani expand. Adani’s own companies, meanwhile, built many of the grand projects that came to symbolise Modi’s ‘Gujarat model’, with its emphasis on infrastructure investment, attracting foreign capital and export industries. There were temperamental bonds too: both were self-made men with little formal education; both were traditional in their tastes, guarded their privacy and were distrustful of outsiders; both spoke in halting English; both, in general, avoided talking to the press. Where other Gujarati industrialists like Mukesh Ambani often settled in Mumbai, Adani stayed in Ahmedabad, becoming the state’s most recognisable businessman. The duo were said to get on well. Adani was loyal too, defending Modi in the aftermath of the bloody Hindu-Muslim riots that hit Gujarat in 2002, a time when Modi faced fierce public criticism.