How the British Empire shaped the nation’s favourite drink: From Victorian high society, to drug trafficking and war with China, what REALLY lies behind the humble cup of tea

For generations, the humble cup of tea has been synonymous with Britishness; it is the liquid heartbeat of the country.

Whether you drink it with or without sugar, with milk or just a slice of lemon, it is the drink par excellence for every problem, celebration and moment of anxiety.

But a new BBC radio series has delved into the dark history of the great British cuppa, revealing its role in the opium trade and subsequent war with China.

Empire of Tea, presented by historian Sathnam Sanghera, also delves into the drink's long association with India and how it first became popular in Britain among high society figures and royalty in the 17th century.

But William Dalrymple's claim in the program that 'extortion, corruption and bloodshed' took place to give the British their brew has attracted criticism, with a rival expert labeling his claims as a 'guilt-tripping expedition'.

Tea was first brought to British shores from China in the mid-17th century, but was initially reserved for royalty, aristocrats and the very wealthy.

It was made more popular by the arrival of Catherine of Braganza, the Portuguese royal who became Queen of England when she married Charles II in 1662.

Her court brought expertise from Portugal's own explorations to Britain.

More tea knowledge came to English shores in 1688, when the Glorious Revolution installed the Dutch William of Orange on the throne.

However, tea remained a luxury until the late 18th century, with a pound of the black stuff costing a British worker the equivalent of nine months' wages.

The ritual of afternoon tea came much later, in the Victorian era.

It is believed that the tradition started when the wealthy Duchess of Bedford enjoyed a crustless cake or bun with a cup of Darjeeling tea when she wanted an afternoon energy boost.

It quickly caught on among fashionable households, and sales of porcelain tea sets soared to accommodate them.

Tea drinking spread further in the 19th century, when it was promoted as a less harmful alternative to beer, port and gin, which were consumed in large quantities.

The dominant one in the tea trade was the East India Company, founded in London at the end of the 16th century.

At its height, the private company – considered the first major multinational – had its own army and the right to mint its own money.

By the end of the 18th century, tea made up 60 percent of the East India Company's trade, generating huge tax revenues for the British government.

To purchase tea at a more reasonable price, the East India Company helped fuel the illegal opium trade.

They smuggled opium from India into China and sold it to willing Chinese traders, then used the proceeds to buy tea.

But Mr Dalrymple, the author of a critical history of the East India Company, said the organization was seen by “raging” Britons as “we would be looking at narco-operators today”.

He said they were seen as “people operating on the edge of legality, if not entirely illegal, and making a profit from the suffering of others.”

In response to this, Dr. Zareer Masani, an expert on the British Empire, told MailOnline: 'Opium was widely used. It was primarily a social drug used in moderation in Chinese upper-class circles.'

He added: 'Tea came from China and opium went to China, but it ignores the fact that this was demand-driven, it actually created employment, although that may be questionable by today's standards.

“This is a very unhistorical way of labeling the East India Company as corporate raiders.”

The Chinese emperor's decision to enforce a ban on the opium trade in 1839 led to military conflict with Britain.

All traders were forced to surrender their opium, which was then publicly burned.

While British traders were left furious over the seizure of what they considered their property, the government intervened and locked horns with China in the First Opium War.

The conflict, which lasted until 1842, ended in a decisive defeat for China.

The Second Opium War, between 1856 and 1860, forced a fractured China to re-legalize the opium trade.

However, by this time the East India Company had started establishing tea plantations in India.

Scottish botanist Robert Fortune disguised himself as a Chinese botanist to enter China and then bring live tea plants to India.

He also brought with him nine workers with an intimate knowledge of how to grow tea to a high standard.

During the 1830s and 1840s, dozens of plantations were established in the Assam region of India.

While Chinese tea remained a luxury product, the Indian variety was marketed as a patriotic drink created in the British Empire.

Queen Victoria was also called in to assist in the propaganda effort. She talked about the quality of tea grown in India after tasting it.

By 1900, Chinese tea – which had previously accounted for almost all of Britain's imports – accounted for just 10 percent of British consumption.

British workers had been consuming tea in large quantities for more than a century. Average tea consumption in 1900 was a whopping 6 pounds per year.

Historian Lizzie Collingham, author of The Hungry Empire, tells the BBC program how 'sugar tea literally fueled the industrial revolution'.

“Ten to fifteen percent of the calories, energy, for the workers in the factories, in the ironworks, came from sugar in the tea,” she said.

She added: 'Between 1663 and 1773, in those hundred years, the increase in consumption has been synchronized, and in parallel.

“So I think it's fifteenfold for tea and twentyfold for sugar. They're going upstairs together.'

The tea break even became a source of industrial unrest in the 1970s and 1980s.

In 1981, workers at British Leyland's Longbridge car factory in Birmingham went on a ten-day 'tea break strike' after bosses tried to reduce the twice-daily breaks they took to drink a brew.

In the end, the attackers achieved a partial victory, with the bosses agreeing to a smaller reduction in break times.