Few things are more synonymous with Britain than “a good cup of tea”. So successful has the United Kingdom been in appropriating tea as its own, and then taking it around the world, that drinking tea is now a ubiquitous part of the pattern of daily life for billions of people.

Tea – more specifically, black tea – is the third most-consumed substance by humans on the planet after air and water. (While writing this piece, I’ve drunk no fewer than 18 cups.) But the comfort of a cup of tea belies a complex history.

Drinking tea became fashionable in England during the 17th century, but it was from the 1800s onwards that it began to reach a mass market, as the notorious British East India Company brought more and more tea to Britain from China.

Britain wanted Chinese goods – especially tea – but had little to offer China, which regulated its foreign trade strictly and would only accept silver. This led to a trade imbalance and to address it, the British state took a two-pronged approach. It began its own tea production in Assam, India, and worked hand-in-glove with its commercial interests in India to also produce vast quantities of opium that it illegally exported to China.

The efforts by the Qing dynasty to suppress the opium trade, that caused mass addiction and had devastating social and economic consequences, led to The Opium Wars. Opium was the commodity ostensibly responsible for the conflict, but it could easily have been known instead as “the Tea Wars”.

Crucial to the marketing of Indian tea was a disparaging racist idea of Chinese tea as tainted by dangerous chemicals and “the residue of dirty and sweaty Chinese labourers” in contrast with supposedly “pure” British tea (grown in India, by Indians, under the supervisions of predominantly Scottish planters).

As both the British Empire and demand for tea grew, other colonies were also used for tea cultivation. The most significant was Kenya where the soil and climate were well suited for tea plantations, and where the British were able to discipline a vast reserve of cheap labour to work the land for British commercial interests, which included several companies that would become world leaders in the tea market.

Tea cultivation in Kenya began on an industrial scale in the 1930s. Today, only China and India produce more tea than Kenya, and the best agricultural land in the East African country is still farmed for multinational tea companies.

An empire built on tea and sugar

The British liked their tea sweet, and so the rise of tea intersects with another commodity that is central to the formation of the modern economic and social order around the world: sugar.

The vast majority of sugar consumed in western Europe from the 17th century onwards was grown in the Caribbean, on sugar cane plantations that ran on the labour of people taken from Africa as chattel and enslaved. Sugar – much of it destined to be spooned into cups of freshly brewed tea – formed a key plank of the triangular trade between Africa, the Caribbean and Europe that made the transatlantic slave trade so profitable for its perpetrators.

Tea is an extremely labour-intensive crop to grow, harvest and process. “It thrives in tropical and subtropical areas with warm temperatures, high humidity, and a great deal of water, sunlight, and well-drained and nitrogen-rich soil,” writes Erika Rappaport. “Once mature, the freshly picked leaves must be processed quickly to prevent spoilage … Ideally all leaf teas should be transported from the field to the cup relatively rapidly or they will lose freshness, flavour, and value.”

Rappaport’s book, A Thirst For Empire: How Tea Shaped the Modern World, shows the crucial role of advertising in first creating and then expanding a thirst for tea around the world.

“By the 1890s, Britons, the Irish, and Australians were primarily drinking the empire’s produce,” she writes. “Yet British markets never seemed capacious enough, and planters felt compelled to conquer vast new colonial and foreign markets. They formed powerful and long-lasting trade associations and raised taxes that paid for massive, and often repetitive, global advertising campaigns. Planters, their allies, and associations thus cultivated many of the technologies and ideologies we associate with the history of modern consumer society.”

There’s nothing more British than a cup of tea

Through powerful advertising campaigns and generations of habitual tea-drinking, a cup of tea has taken on a singular symbolic potency in the British (and especially English) imagination.

It was a perfect fit for the needs of weary workers in the mills and factories of industrial England, just as frazzled office workers today will usually stop for at least one "tea break" in the course of the working day. A "cuppa" brings comfort to solitary drinkers, but it also functions as a social lubricant.

Through its marketing, and ensuing social customs, tea has taken on a curiously connective function across the key dividing lines of British society. It lends its name to both the “high tea” enjoyed by the upper classes, and “builder’s tea” (strong, and brewed in a mug from a tea bag and not a teapot with loose leaves) as supposedly prepared by construction workers.

“Tea is shit,” wrote Joel Golby in a self-deprecating column that outraged and amused the British public in equal measure. "It’s a lukewarm mug of leaf water, presented as a cure-all for life’s ills. "Nice cup of tea," people say, when you’ve watched a vivid car accident or been given a terminal diagnosis, or gone for a walk and it’s started raining. Whether the mafia has kidnapped you and made you kill a man with a gun to win your freedom or if you’ve done quite badly in an exam, someone will say: "Let me get you a nice cup of tea."

So ubiquitous is the love of tea supposed to be that just about the most damning thing you can say about another person – while remaining polite, of course – is: “they aren’t my cup of tea”.

Sharing a cup of tea offers the sentimental idea that, fundamentally, everyone wants the same thing. But it is a fantasy of national cohesion that only holds together by obscuring the actual conditions under which tea is grown and processed. The distinctive English character of tea has been refined over centuries by abstracting the idea of the commodity itself from the place and people that actually cultivated it.

So, tea works not just as a metaphor for Britishness but also for British imperialism. "That is the outside history that is inside the history of the English,” wrote the late Jamaican-British sociologist Stuart Hall.

"People like me who came to England in the 1950s have been there for centuries; symbolically, we have been there for centuries. I am the sugar at the bottom of the English cup of tea. There are thousands of others beside me that are, you know, the cup of tea itself ... There is no English history without that other history."