The mysteries of the North Sea: a lost land bridge, a geopolitical crossroads, and a tourist haven - The North Sea—the northeastern arm of the Atlantic Ocean—is located between the British Isles and the mainland of northwestern Europe. Its waters have had a strong influence on European history, providing access for commerce and conflict. The sea is also the source of numerous myths and legends. Incredibly, however, the North Sea covers an area that was once terra firma, an enormous land bridge that connected Britain to continental Europe.

Intrigued? Click through and find out more about how this sea was formed and the role it has played in geopolitical and military affairs, and its appeal as a tourism destination.

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Doggerland -

Did you know that an area of land once connected Britain to continental Europe? It was known as Doggerland, but it was flooded by rising sea levels around 6500–6200 BCE. Pictured is a Doggerland recreation in the Naturalis Biodiversity Center in Leiden, Netherlands.

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Dogger Bank -

Doggerland was named after the Dogger Bank, a large sandbank in a shallow area of the North Sea (denoted in the red outline).

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Doggers -

Dogger Bank, meanwhile, was named after the doggers, medieval Dutch fishing vessels.

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The Storegga Slide -

The North Sea was dry land until around 6100 BCE when a colossal tsunami—one of the biggest ever recorded on Earth and triggered by a violent landslide (Storegga Slide) in Norway—submerged the low-lying plains to create what is now the North Sea. In doing so, Britain became an island nation.

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Roman conquest of Britain -

It was only after the Roman invasion of Britain in 43 CE that seaborne trade on the North Sea began. The Romans established organized ports, which increased shipping and encouraged sustained commerce.

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Viking invasion -

The fall of the Western Roman Empire prompted the overrunning of Britain by numerous Germanic tribes, including the Goths, Saxons, and Angles, all of whom used the North Sea to reach their destination. But it was the Viking invasion beginning in 793 that saw the North Sea being used by Norse warriors as a jumping off point for raids, invasions, and colonization of Britain, France, Iberia, the Mediterranean, and the Atlantic.

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Hanseatic League -

In the 15th century, the Hanseatic League, a medieval confederation of central and northern European towns and merchant guilds, dominated sea trade in the North Sea and Baltic. Vessels such as the warship Adler von Lübeck—one of the largest ships in the world at her time—served as formidable escorts.

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Anglo-Dutch Wars -

The first significant naval action to take place on the North Sea was witnessed during the Anglo-Dutch Wars between 1652 and 1673.

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Battle of Dogger Bank -

During the First World War, the North Sea became the main theater of battle for surface action. On January 4, 1915, the British Navy achieved a victory at the Battle of Dogger Bank, with the German armored cruiser SMS Blücher (pictured) among the vessels sunk.

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Battle of Jutland -

The Battle of Jutland, which took place in 1916 and unfolded off the North Sea coast of Denmark's Jutland Peninsula, was the largest naval battle and the only full-scale clash of battleships in that war.

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German invasion of Norway -

During the Second World War, the North Sea provided a convenient sea route for German forces departing occupied Denmark for the invasion of Norway in 1940, codenamed Operation Weserübung.

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Air and sea operations -

The North Sea was heavily mined by Axis and Allied powers during the Second World War. Pictured in 1941 are minelayer units, escorted by German FW 200 (Condor) long range sea reconnaissance planes.

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Aerial warfare over the North Sea -

Large scale aerial warfare took place over the North Sea throughout the early years of the Second World War. Later, however, with the Luftwaffe largely defeated, the skies belonged to the Allies. In this rare color image, American B-24 Liberator heavy bombers (from the 8th Air Force) with an escort of P-51 Mustang fly over the sea towards occupied Europe.

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Passenger ferry services -

Passenger ferry and boat train services serving the North Sea began operating out of Harwich in England to ports in Belgium in the early 20th century. But it wasn't until the 1960s and the advent of mass tourism that regular scheduled crossings between the United Kingdom and the European continent using the North Sea began to rival English Channel ferry route options.

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MS Herald of Free Enterprise disaster -

On March 6, 1987, the MS Herald of Free Enterprise roll-on/roll-off ferry capsized moments after leaving the port of Zeebrugge in Belgium. Bound for Dover, the vessel had departed with her bow door open. This allowed the sea to immediately flood the decks and within minutes the stricken ship was on its side in shallow water, killing 193 passengers and crew.

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Oil and gas exploration -

Commercial extraction of oil on the shores of the North Sea dates back to 1851. Offshore North Sea oil was discovered in the early 1960s. In 1971, the giant Brent oil and gas field was discovered. Brent crude is still used today as a standard benchmark for pricing oil.

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Piper Alpha disaster -

The inherent danger of North Sea oil and gas exploration was first made obvious in 1965 with the collapse of the Sea Gem oil rig off the coast of Lincolnshire. Thirteen people died. But it was the Piper Alpha oil platform explosion on July 6, 1988, which killed 165 men, that remains the world's worst offshore oil disaster in terms of lives lost and industry impact.

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Sea dimensions -

The North Sea is more than 970 km (600 mi) long and 580 km (360 mi) wide. It reaches 725 m (2,379 ft) at its deepest point.

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Origins of the North Sea name -

The North Sea has had various names throughout history. Roman author Pliny the Elder recorded it as Septentrionalis Oceanus, or "Northern Ocean." Claudius Ptolemy's 'Geographia' from the 2nd century CE noted it as Oceanus Germanicus, or "German Sea." Its modern name probably came into English via the Dutch Noordzee, which directly translates as North Sea.

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HMS Gloucester -

HMS Gloucester floundered in 1682 on a sandbar off the Norfolk coast. Over 100 crewmen perished, though the Duke of York (the future King James II) survived. The shipwreck was located in 2007, but the discovery was only made public in 2022. It's been hailed as the most important find since the Mary Rose, in 1971.

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North Sea fishing -

The North Sea is Europe's main fishery, accounting for over 5% of international commercial fish caught. Despite the reformed Common Fisheries Policy, overfishing remains an issue, to the point where huge areas of the North Sea have previously been declared off limits and fishing quotas slashed in an attempt to rescue dwindling North Sea stocks from the point of extinction.

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Devil's Hole -

The North Sea is home to a series of deep trenches known collectively as the Devil's Hole. The undersea feature is about 200 km (125 mi) east of Dundee, Scotland. The trenches are as deep as 230 m (750 ft) with many a fishing vessel losing its trawler nets on their steep, ragged slopes.

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Horns Rev 1 Offshore Wind Farm -

In 2002, the initial stage of the first large-scale offshore wind farm in the world, Horns Rev Offshore Wind Farm, came online. By 2019, Horns Rev 1 was fully operational. It's located in Danish waters of the North Sea.

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The Hadleigh Gang -

The 18th-century English smugglers known as the Hadleigh Gang operated out of the market town of Hadleigh in Suffolk. Numbering around 100 men, they would take delivery of contraband hauled ashore along the coast from North Sea privateers and buccaneers.

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Spotting a sea serpent -

According to Norse mythology, Jörmungandr is a huge sea serpent that plagues mariners in North Sea waters. In 1927, three men taking a walk on Eccles Beach in Norfolk, England, reported seeing an "unusual form traveling swiftly about one mile from the shore." They added that "from a distance, it appeared to be a form of a huge serpent about 30 or 40 feet in length and skimming the surface of the water in a wormlike movement but traveling at a terrific speed, certainly not less than one mile a minute." The local newspaper, Eastern Daily Press, ran the story.

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Lost town of Dunwich -

Dunwich was the capital of the Kingdom of the Angles during the Anglo-Saxon period. A thriving port town in Suffolk, England, it eventually fell victim to a storm surge and subsequent coastal erosion and was swallowed up by the North Sea. Today described as Britain's Atlantis, the lost town lies 15 m (50 ft) below the waves and up to 1.5 km (1 mi) from the beach. Pictured in 1904 is the ruins of All Saints' Church, the last of Dunwich's ancient churches to be lost to the sea, finally being submerged in 1922.

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North Sea flood of 1953 -

On January 31, 1953, a similar tidal surge following a violent storm struck the Netherlands, north-west Belgium, England, and Scotland. Pictured is a village flooded in Essex.

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Widespread damage and loss of life -

The combination of wind, high tide, and low pressure caused the sea to flood land up to 5 m (18 ft) above mean sea level, resulting in widespread damage and the loss of 1,836 lives. Most of the casualties occurred in the southern Dutch province of Zeeland (pictured).

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Biodiversity -

The North Sea is rich in biodiversity, its coasts home to numerous nature reserves that provide sanctuary for a staggering array of marine mammals and millions of birds. The Wadden Sea, an intertidal zone in the southeastern part of the North Sea that encompasses areas of the Netherlands, Germany, and Denmark, is a designated UNESCO World Heritage Site.   

Sources: (ScienceDirect) (Eastern Daily Press) (BBC) (Britannica)

See also: Cities that could disappear by 2030 due to rising sea levels 

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