Image copyright National Maritime Museum Image caption Smuggler being chased by the Royal Navy. Virtually every seaside community in Britain understood its share of smuggling in the 18 th Century

A boat beaches in a lonely cove at night, the crew hurriedly unloading its cargo of tea to waiting men and pack horses while armed lookouts stand guard against a surprise swoop by the revenue humankinds.

It may be a stereotypical image, but in the 18 th Century, a cuppa was in such high demand that many Britons were willing to peril jail for the privilege.

In fact, this kind of smuggling was a vital part of Britain’s economy for some 200 years.

It was a trade triggered by increasingly high tariffs or duties, taxes a seller would have to pay to legally import tea.

The duties on importing tea reached a staggering 119% in the 1750 s – which meant that if you are able avoid paying the tax, the cost of your brew dropped by more than half.

Image copyright Getty Images Image caption Tea became hugely popular in Britain in the 1700 s

Not amazingly many patrons turned to the smugglers, who were willing to peril incarceration or have their ships destroyed and goods grabbed unless they are caught.

Free trade and smuggling are closely linked.

When import taxes or tariffs are low, there’s not much gain to be made from smuggling.

Conversely, when both governments constructs it expensive to legally import items it promotes smugglers who can undercut the official price.

Tea taxes

Tea was one of the most important items illegally brought into Britain in the 18 th Century – everybody wanted to drink it, but most has not been able to afford it at the official price.

Image copyright Getty Images Image caption Tea chests in London in the 1950 s – the nation’s love affair with the drink has suffered

In an age before income tax, tea duties accounted for 10% of government revenues, which was enough to pay for the Royal Navy, but as tariffs on it reached 119% it committed smugglers their chance.

“If “youve had” high tariffs and goods people wanted, it committed smugglers a business possibility, ” says Exeter University historian Helen Doe.

More than 3,000 million tonnes tea was smuggled into Britain a year by the late 1700 s, with merely 2,000 tonnes imported legally.

In some areas whole communities were dependent on smuggling, from landowners who might finance the operation down to the fishermen who might be crewing the boats.

Smuggling operations

There were three major types of smuggling, says Robert Blyth, senior curator at the National Maritime Museum in London.

Image copyright National Maritime Museum Image caption A romanticised view of the smuggling trade; in reality smugglers often used menaces of violence against traditions humankinds

“There’s small-scale smuggling, where you might row your barge out to meet a vessel and take off some of its cargo to sell illegally, the ship’s captain proclaiming the missing cargo as ‘spoiled at sea’ when it gets to port to officially unload the rest, ” he says.

“Then there are commercially organised groups bringing contraband into harbours across the UK in a sophisticated operation.

“Finally, you have simple steal and pilfering in major ports like London from ships that have already moored, but have not yet been checked by the revenue.”

Swedish traders

It wasn’t merely the British who were developing a taste for tea. The popularity of the drink in Sweden meant the country also played an important role in 18 th Century smuggling into Britain.

Image copyright Thinkstock Image caption Gothenburg was the base for the Swedish East India Company’s runnings

Swedish East India Company sellers were able to buy the best quality Chinese tea because unlike other European countries they were prepared to pay in silver – rather than seeking to barter or trade.

Quite a few were actually Scottish, political refugees who had fled to Sweden after the failure of the 1745 Jacobite uprising, and who thus understood little incorrect in avoiding paying tax to Britain’s Hanoverian government.

So popular was this trade that newspapers in Scotland and northern England openly carried adverts for this smuggled tea, called “Gottenburgh Teas”.

Image copyright Getty Images Image caption Building specialised docks with guarded warehouses helped cut down steal of goods once ships had reached London

For many tea traders in Britain, buying smuggled tea induced sense, says Derek Janes, a history researcher at Exeter University.

“Britain’s own East India Company had a monopoly on tea importations, so if an Edinburgh merchant wanted to buy it you had to go to London, you had to pay to bringing it back to Scotland – and you had to pay upfront.

“But if you bought it from the smugglers it would be half the cost – with no tax to pay – they would deliver to your doorway and you would get up to 4 months credit. A much better service! “

One of those involved in this trade was John Nisbet, who became rich enough to board architect John Adams to design his harbourside mansion in Eyemouth in the Scottish margins, complete with hidden partitions for the smuggled tea.

Often when the customs officials got a tip-off about his ship it was too late – the cargo had already been smuggled ashore. And if a smuggler did have his goods grabbed, he had been able to sometimes negotiate world prices to buy it back from the government.

“John Nisbet had a ship and cargo grabbed, but you can see the lawyer for the board of trustees of the traditions in Edinburgh say that the eyewitness had disappeared, so the customs did a bargain. He paid 250 to get it all back, which still left him in gain, ” says Mr Janes.

Increased policing

By 1784, the governmental forces realised high tariffs were generating more difficulties than they were worth and cut tea duties to merely 12.5%, making tea affordable for most people. The change meant smugglers switched to bring back feelings and wine instead.

Image copyright Getty Images Image caption The purpose of the Napoleonic conflicts understood the Royal Navy in undisputed command of the Channel, making it much harder for smugglers to avoid detection

The Napoleonic conflicts understood an upsurge in smuggling, but after 1815 with the Royal Navy in undisputed command of the sea, its days were numbered.

Ultimately, many smugglers failed. In the long run, the business did not produce enough cash to compensate for health risks of losing stock or ships to the customs. John Nisbet may have been able to afford a fine home but even he went bust eventually, the result of one too many cargo convulsions.

In the end, it was economics that ultimately put an end to the smuggling era. Britain’s adoption of a free trade policy in the 1840 s reduced import duties significantly, making smuggling no longer viable.

And thanks to that shift in policy, you can now sit back, relax and enjoy a nice cup of tea without any anxieties of going to prison.

Follow Tim Bowler on Twitter @timbowlerbbc