The English East India Company, founded in 1600, was established for trading. But as the powerful multinational corporation expanded its control over India in the late 18th Century, it commissioned many remarkable artworks from Indian painters who had previously worked for the Mughals. Writer and historian William Dalrymple writes about these hybrid paintings which explore life and nature.
Calcutta in the late 1770s was Asia's biggest boom town: known as the City of Palaces, the East India Company's bridgehead in Bengal had doubled in size to 400,000 inhabitants in a decade.
It was now unquestionably the richest and largest colonial city in the East - though certainly not the most orderly.
"It would have been so easy to turn it into one of the most beautiful cities in the world," wrote the Count de Modave, a friend of Voltaire who passed through at this time. "One cannot fathom why the English allowed everyone the freedom to build in the most bizarre taste, with the most outlandish planning."
Nor were visitors much taken by its English inhabitants. Most had come East with just one idea: to amass a fortune in the quickest possible time.
Calcutta (now Kolkata) was a city where great wealth could be accumulated in a matter of months, then lost in minutes in a wager or at the whist table. Death, from disease or excess, was a commonplace, and the constant presence of mortality made men hard and callous.
Rising with Olympian detachment above the mercantile bawdiness of his contemporaries was the rotund figure of the chief justice of the new Supreme Court, Sir Elijah Impey.
A portrait of him by Johan Zoffany still hangs, a little lopsidedly, in the Calcutta High Court. It shows him pale and plump, ermine gowned and dustily bewigged.
Impey was, however, a serious scholar and unusual in taking a serious interest in the land to which he had been posted.
On the journey out to India, a munshi (administrator) had accompanied him to teach him Bengali and Urdu, and on arrival the new chief justice began to learn Persian and collect Indian paintings. His house became a meeting place where the more cultured elements of Calcutta society could discuss history and literature.
Impey and his wife Mary were also greatly interested in natural history and began to collect a menagerie of rare Indian animals.
At some stage in the mid-1770s, the Impeys decided to bring a group of leading Mughal artists - Sheikh Zain ud-Din, Bhawani Das and Ram Das - to paint their private zoo.
It was probably not the first commission of Indian artists by British patrons. "The Study of Botany is of late Years become a very general Amusement," noted one enthusiast, and we know that the Scottish nurseryman James Kerr was sending Indian-painted botanical drawings back to Edinburgh as early as 1773.
But the Impeys' albums of natural history painting remain among the most dazzlingly successful of all such commissions: today, a single page usually reaches prices of more than £330,000 ($387,000) at auctions, and the 197 images from the Impey Album are now widely recognised as among the very greatest glories of Indian painting.
This month, for the first time since the Impey Album was split up in the 18th Century, around 30 of its pages will be reassembled for a major exhibition in the Wallace Collection in London.
Forgotten Masters: Indian Painting for the East India Company celebrates some of the extraordinary work which resulted from commissions made by East India Company patrons from master Indian artists between the 1770s and 1840s.
It will be a unique chance to see some of the finest Indian paintings which are now scattered in private collections around the world.
The three artists who Impey summoned to his fine classical house in Middleton Street were all from Patna, 200 miles (320km) up the Ganges.
The most prolific was a Muslim, Shaikh Zain-al-Din, while his two colleagues, Bhawani Das and Ram Das, were both Hindus.
Trained in the late Mughal style and patronised by the Nawabs of Murshidabad and Patna, they quickly learned to use English watercolours on English Watman watercolour paper, and take English botanical still lives as their models. In this way an extraordinary fusion of English and Mughal artistic impulses took place.
Zain ud-Din's best works reveal a superb synthesis between a coldly scientific European natural history specimen illustration, warmed with a profoundly Indian sensibility and vital feeling for nature.
At his best - whether by instinct or inherited knowledge and training - he channels the outstanding Mughal achievement in natural history painting of 150 years earlier, when the great Mughal artist Mansur painted animals and birds for the Emperor Jahangir.
Nowhere are the merits of Company Painting better illustrated than in Zain ud-Din's astonishing portrait of a Black Headed Oriole (No. 27).
At first glance, it could pass for a remarkably skilful English natural history painting. Only gradually does its hybrid origins become manifest.
The brilliance and simplicity of the colours, the meticulous attention to detail, the gem-like highlights, the way the picture seems to glow, all these point unmistakably towards Zain ud-Din's Mughal training.
An idiosyncratic approach to perspective also hints at this background: the tree trunk is rounded, yet the grasshopper which sits on it is as flat as a pressed flower, with only a hint of outline shading to give it depth - the same technique used by Mansur.
Yet no artist working in a normal Mughal atelier would have placed his bird detached from a landscape against a white background, with the jackfruit tree on which its sits cut into a perfect, scientific cross-section.
Equally no English artist would have thought of painting the bark of that cross section the same brilliant yellow as the oriole; the tentative washes of a memsahib's watercolour are a world away.
The two traditions have met head on, and from that blinding impact an inspirational new fusion has taken place.
Bhawani Das, who seems to have started off as an assistant to Zain ud-Din, is almost as fine an artist as Zain ud-Din.
He is acutely sensitive to shape, texture and expression, as for example in his celebrated study of a great fruit bat with the contrast between its soft, furry body with the angular precision of its blackly outstretched wings, as if it were some caped Commendatore ushering a woman into a Venetian opera rather than a creature in a colonial menagerie.
Now, for the first time, the work of these great Indian artists painting in this brilliantly hybrid Anglo-Indian style are beginning to get the attention they deserve.
The first-ever museum show of this work in the UK aims to highlight and showcase the work of a series of extraordinary Indian artists, each with their own style and tastes and agency. Indeed the greatest among them - such as Zain ud-Din- deserve to be remembered as among the most remarkable Indian artists of all time.
William Dalrymple is the author, most recently, of The Anarchy: The Relentless Rise of the East India Company and Forgotten Masters: Indian Painting for the East India Company (Bloomsbury)