Food: Like real men today, the Mughal rulers of northern India believed that meat helped them acquire semen, and with it strength and courage. Hindus, on the other hand, were usually vegetarian. For them, properly regulated food was the route to good health and spiritual enlightenment.
The tastes of East India Company officials naturally lay with the Mughals. As merchants, they felt obliged to impress local princes with gargantuan feasts in which mountains of meat were presented alongside curry and rice.
In the early days, the British borrowed the food, dress and habits of their Indian counterparts. Some even had their own harem. The harem remained in India, but the food travelled back to England, and the recipes for pilau first appeared in an English cookery book in 1747.
By 1800 the concept of "curry" was well-established in Britain. It was a bastardised dish, adapted to British kitchens, which took its name from "caree", the Portuguese word for an Indian broth. In the Victorian period, curry became the staple of the thrifty middle-class housekeeper, who used it as a vehicle for leftovers - a practice that would have horrified most Hindus. Back in India, however, the British abandoned their attempts at multiculturalism. A typical menu of 1873, for a dinner in Bombay, is a gruesome litany of fillets of fish in parsley sauce, breast of mutton compote, mutton chicken pie and baked custard.
Indians were unimpressed by British cooking but they did begin to use new vegetables and drink tea. Tea, heavily promoted by the Indian Tea Association, was not subject to caste rules, so it allowed people of different social levels to socialise together. As the independence movement grew, educated Hindus even contemplated eating meat. "It began to grow on me," said Gandhi, "that meat-eating was good, that it would make me strong and daring, and that, if the whole country took to meat-eating, the English could be overcome."
But his experiment in meat-eating was not a success, and as a student in London he lived mainly on porridge.
Ironically, it was only when the British Empire had come to an end that the British began to enjoy curry again. The curry house, that enduring feature of the modern British landscape, originated in the 1920s when Bengali sailors set up cafes in London's East End for hungry seamen. There are now about 8,000 Indian restaurants in Britain, and most of them are run by Bangladeshis. They come from Syhlet, a small area on the north-eastern border whose speciality is a pungent sauce made from rotten fish. In the days of the Raj, many Syhletis became stokers on British ships - a hot and dangerous job that they abandoned as soon as they could find a foothold elsewhere.
This usually meant work in the restaurant trade. The seamen's cafes expanded into curry houses, serving chicken vindaloo to British boozers, and then into more sophisticated establishments in the 1970s, when foreign travel and the writings of the post-war cookery writer Elizabeth David made people more adventurous in their tastes.
Indian food has now travelled the world, acquiring new identities all the way. Ironically, a food tradition that was originally intensely regional and socially regulated has become global and multicultural. There is a pocket of Mexican-Hindu food in California, an Indo-Fijian cuisine in the Pacific and a fast-food chain in Japan where you can buy cheese or frankfurter curries in seven levels of spiciness. In India itself, a new cuisine is developing, as delicious, subtle and varied as the traditional food, but more suited to modern urban lifestyles.
The author of this illuminating book is an historian who taught at Warwick University. She begins - rather too predictably - in a curry house in Leamington Spa and calls the book a biography (which it isn't). But she goes on to develop a well- researched and even-handed analysis of cultural appropriation. This is often presented as a crime peculiar to the ruling elites, but probably it is no more than human instinct, central to our evolution.
Her recipes include a 1970s British curry, with celery and soy sauce, as well as a Goan vindaloo that combines marinated pork (a Portuguese speciality) and hot south Indian spices. This too is fusion.
Lucy Trench works at the Victoria and Albert Museum. Both her grandfathers worked in the Indian political service and as a baby she went on safari in Kenya with the maharaja of DungarpurFood
Curry: A Biography By Lizzie Collingham. Chatto & Windus, 318pp. £16.99