In 2016, the United Kingdom voted to leave the European Union, sparking years of heated debate, political drama, and enough paperwork to make a bureaucrat weep.

But as it turns out, this wasn’t Britain’s first dramatic exit from Europe.

The original “Brexit” happened long before anyone had ever heard of Article 50 or worried about the Irish backstop.

This separation was far more literal, and it reshaped the map of Europe in a way that no political decision ever could.

Brexit 1.0 — not with a referendum, but with a splash.

It’s 8,500 years ago, and the world looks very different from what we know today.

The last Ice Age has ended, and the Earth is warming up. Sea levels are rising, reshaping coastlines and changing the lives of our ancient ancestors.

In what we now call northwestern Europe, a dramatic event is about to unfold — one that will literally shape the future of a nation.

How Great Britain became an island

You might call it “The Original Brexit,” though this separation from Europe happened long before any political unions or referendums.

This is a story of nature’s power, of changing landscapes, and of how a piece of land broke free from a continent.

At this time, 8500 years ago, Britain isn’t an island yet. It’s connected to mainland Europe by a strip of land called Doggerland, now buried far beneath the North Sea.

Doggerland isn’t just a thin bridge of earth — it’s a vast, low-lying plain stretching from what’s now the east coast of Britain to the present-day Netherlands, Germany, and Denmark.

Doggerland is home to forests, wetlands, and meandering rivers. It’s a rich hunting ground for our Mesolithic (Middle Stone Age) ancestors, who roam the land following herds of animals and gathering plants.

The big flood

But big changes are coming. As the Earth continues to warm, massive ice sheets that once covered much of the northern hemisphere are melting.

All this water is flowing into the oceans, causing sea levels to rise. Slowly but surely, Doggerland is flooding. The process is gradual at first — low-lying areas become wetlands, rivers grow wider, and the sea creeps inland bit by bit.

For the people living in Doggerland, life is becoming increasingly challenging.

Hunting grounds are shrinking, and communities are forced to move to higher ground.

Some might have migrated to what would become Britain, while others headed east to mainland Europe.

It’s hard to imagine what these ancient people thought about the changing world around them. Did they tell stories about the land being swallowed by the sea? Did they have legends about angry water spirits flooding their homes?

The big wave

Now, here’s where things get really interesting. About 8,200 years ago, a massive underwater landslide occurred off the coast of Norway.

This event, known as the Storegga Slide, was truly epic.

Imagine a chunk of seabed the size of Scotland suddenly breaking off and sliding down into the deep ocean. The Storegga Slide wasn’t just big — it was one of the largest known underwater landslides in history.

This enormous slip triggered a tsunami — a giant wave that raced across the North Sea.

When it hit the already fragile and partly submerged Doggerland, the results were catastrophic. The wave, which might have been as high as 5 meters or 16.4 feet (that’s about as tall as a giraffe!), swept over the low-lying land.

In one fell swoop, it likely drowned many of the remaining animals and people living there and accelerated the flooding process that was already underway.

The disappearance

After the tsunami, what was left of Doggerland quickly disappeared beneath the waves. The rising seas finished what the giant wave had started. The highest parts of Doggerland became islands for a while, but eventually, they too were swallowed up by the North Sea.

And just like that, Britain became an island.

It’s wild to think about, isn’t it?

The map of Europe changed dramatically in what was, geologically speaking, the blink of an eye.

The people living in Britain at the time might not have immediately realized they were now cut off from the mainland. But over time, as traders and travelers found they could no longer walk to the continent, the reality would have set in.

This separation had a profound impact on the development of Britain. As an island, it was now more protected from invasions (though as history shows, it wasn’t impossible to conquer).

The isolation also meant that plants, animals, and even human cultures on the island could develop in unique ways.

Present day

Today, if you were to drain the North Sea, you’d find the remains of Doggerland on the seabed. Fishermen sometimes dredge up ancient bones, tools, and even bits of wood from the forests that once grew there.

Scientists and archaeologists are fascinated by this “lost world” and are using advanced technologies to map and study the submerged landscape.

It’s a focal point of human anthropology and evolution studies too.

The story of how Britain became an island is more than just a geological curiosity. It’s a reminder of the tremendous forces that shape our planet and how vulnerable we are to environmental changes. It shows us that landscapes we think of as permanent can change dramatically, sometimes in the space of a human lifetime.

The bottom line

Our ancestors survived this changing world, adapting to new coastlines and ways of life. They passed on their genes, their tools, and their stories, leading eventually to the Britain, North Sea, and Centrals European countries we know today.

Next time you look at a map of Britain or read about Brexit, think about Doggerland and the ancient Brexit that created this island nation.