The crash it warned of came with the ending of the American Civil War in 1865 and the tapering demand for cotton. On the Liverpool market, the price of cotton fell from 20 to 10 pence. The bubble broke and panic spread in Bombay as people tried to offload shares in worthless companies. By mid-May, one by one, the city’s wealthy businessmen went bankrupt. The swollen giddy money market contracted and overdue bills piled up at the Bank of Bombay. A commission was set up to inquire into the bank’s failure.

Dinsha E Vachcha, in his book, A Financial Chapter in the History of Bombay City, writes: “Lakhs were given away on personal security … These again were permitted to be renewed to an indefinite extent at any rate till the mischief was done irretrievably.” Premchand was allowed by other shareholders and directors “to withdraw vast amounts of money from the Bank to finance his multitudinous schemes – directly and indirectly Rs 1.38 crore … a colossal and unheard-of advance” and also, half of the Bank of Bombay’s total capital.

As the doomsayers had predicted, thousands of shareholders were wiped out and many households in Bombay teetered on the verge of ruin. The saga of the cotton boom with its magical possibilities and eventual collapse became a morality tale in the consciousness of urban India. But the phenomenon also had ramifications for people outside of cities. The alternating phenomena of enrichment and impoverishment spread like wildfire through the rural districts of western India.

One area where they percolated was the villages around the Tapi where I last left my imaginary khalasi and his neighbours, on the riverbank, praying in the Kinara Mosque in the early 16th century. Their descendants were Sunni Bohras, a Muslim sect of trader-agriculturists which included, on the one hand, a leading Surat-based trader like Mulla Abdul Ghafur and on the other, the indigent farmer community on the riverbank. An article in a community publication describes them in the late 1800s as “toiling tillers, with calloused hands, and sunburnt skins, illiterate and ignorant … a colony of poor, struggling peasants … like hundreds of others of its kind and size throughout British India”.

One imagines that much had happened to the khalasi’s grand progeny over three hundred years. The spread of famine, drying out crops and spreading hunger. Disease, chronic, wasting fevers depleting bodies, hastening death. Political shifts, rulers passing the baton from one to another and extracting profits in the form of new, onerous taxes. Yet through all these vicissitudes, they continued to live their simple lives, fishing in a clear lake and cultivating their plots of land, growing, among other things, brinjals, which the Census office reported were “soft and full of agreeable taste”.

And then came the cotton mania, hitting the bucolic community like a tornado. The “rural Bohras are not in so good a condition,” the 1877 Gazetteer reported. “Many of them contracted expensive habits during the prosperous times of the American war, and have fallen into debt.”

The situation created by the cotton boom seems unprecedented, for this time life did not continue as before, with the farmers surmounting adversities with stoic resignation. Something shifted permanently. What brought about the shift? What made the villagers seek to completely alter their way of life? One cannot say for sure, but what is known is that in the 19th century, a certain Ismail Ibrahim Turawa from Surat and a Haji Eesop Boatawala from Rander had gone to a little island called Mauritius, adrift miles off the African coast, and become successful businessmen there.

Presumably, they sent home news of the proliferation of Indian indentured workers on the island, of thousands of Indians needing to be fed, clothed and supplied with items of daily use. In 1877 Queen Victoria, declared Qaisar-i-Hind or Empress of India, in the grand style of the Moghuls, reiterated the sentiments of her 1858 Proclamation binding the Crown to “the natives of our Indian territories by the same obligations of duty which bind us to all our other subjects”. By then indentured workers were in South Africa, the land where diamonds and gold had been discovered. A new geography of empire beckoned, or so it seems from the community’s account which claims: “To this humble and obscure community came tales of the discovery of Gold in a far-off land, at the bottom of the continent of Africa, in a country called the South African Republic which we know as the Transvaal.”

Some enterprising villager must have worked it out: the price of tickets, the timing of ships from Bombay port and a way to get to the city. Assorted unconnected elements came together – dismal economic prospects, a feeling of belonging to an empire, spare cash from the cotton mania, profits jingling in threadbare pockets. A long-abandoned memory of the sea and distant lands was triggered. Something stirred the depths, bringing to the surface an impulse, old and long-forgotten. “Attracted by the lure of adventure and wealth, and the chance of making a new life in an unknown land,” continues the author of the community souvenir, “a number of energetic and adventurous young men set sail braving the open sea.”

An inherited rhythm of the ocean, a long-buried restlessness hit the progeny of the khalasi and once loosened, these tremors surged through the medieval villages and were impossible to hold back.

Young men sliced up kerosene tins and hammered and nailed them to make trunks. They threw their meagre belongings into them. And they left. Like waves nudging each other, swelling into a tide, moving, irresistible, they went. From villages with lilting names: Kholvad, Kathor, Barbodhan, Lajpur, Navsari, from all around the Tapi. Some went to Mauritius, some to Natal or the Transvaal. One after another they flung themselves into an unknown future starting with a “treacherous sea voyage”.

They were “passenger Indians”, the term that would emerge to describe migrants who travelled outside of official arrangements between Indian and overseas governments, who left voluntarily, at their own expense. “Illiterate and ignorant” youths, from a “humble and obscure community” left by the thousands starting in the mid-nineteenth century to establish new communities in faraway lands, just as their ancestors had done many lifetimes ago.

Surat is a three-hour train ride out of Mumbai. On my way to a more distant town, I have often caught a glimpse through the window of its neon hotel signs haloed by dust and exhaust fumes, a dispiriting sight, which aligns with its reputation as a dynamic small-scale manufacturing centre. Thousands of migrant workers from other parts of the country live and work in its dingy workshops, many of them for the diamond-processing industry of which Surat is a hub: over half of all diamonds hewed out of mines in Australia, the Democratic Republic of Congo, Botswana, Russia and South Africa in a given year are cut and polished here, doubling their value in the world market.

I walk around the old city of Surat and find it hard to tell that this was once a great port or the place where the British established its first significant foothold on Indian soil. Across the road from the fort is a library built in 1850 by a pearl dealer, Rao Bahadur Naginchand Jhaveri. Somewhere close by, amidst a snarl of two-wheelers and smoke, is a Moghul-era building housing the Surat Municipal Corporation and an 80-foot clock tower donated by a Parsi philanthropist. Of the erstwhile English Company’s factory, there is no sign; there has not been for a while, for Henry George Briggs, looking for it while writing his Cities of Gujarashtra in 1847, claimed it had disintegrated into a “noble pile”.

An air of slow decrepitude hangs over the old markets where I come across fruit stalls, heaps of plastic boxes, cheap clothes leaning against a sagging wall and a cage of parrots dangling on a small dirty porch. Lanes and public squares, misshaped by clumsy efforts to meet the requirements of new traffic, lead to residential spaces where mossy Art Deco façades are interspersed with small temples, bejewelled deities glimmering in their dark recesses. I pass parked two-wheelers, a drainpipe with a shredded kite and a board with a newly painted sign for “Happyy Men’s Tailors” above a bright, tube lit basement.

The Lakhpati Hospital extension is a two-storeyed block of concrete punctuated by windows with horizontal grilles. A banner hanging on a gate at ground level offers a toll-free number for a dengue or malaria test. Another has a slogan above an image of a finger pressing a button: “Your Vote is the Life of Democracy”. Two closed white jeeps with a red stripe on the sides and an ambulance light on the roof are parked outside the entrance. Clothes dry on a balcony. A street sign says Muglisara, Ward 13. This was where the Killavala house stood before the municipal corporation requisitioned the plot for a hospital extension. It was a large house, one, maybe two, storeys high, and straddling the space between two lanes. My ancestor Gangadas who worked at the fort had a son, Nandkor, and a daughter, Alka. Nandkor had two sons, Rangildas and Parmanandas. Parmanandas was married to Gangaben and they had three sons, Dahyalal, Chhaganlal and the youngest, my great-grandfather, Mohanlal.

Excerpted with permission from The Other Mohan in Britain’s Indian Ocean Empire: A Personal Journey into History, Amrita Shah, HarperCollins India.