BRUSSELS: The European Union created by the Treaty of Rome 60 years ago is far from the first vision of a united Europe.

Here are some other notable examples from history of when Europeans attempted to unite under one flag, people or nation.

Roman Empire

WHEN: 27 BC to 476, the empire falling to the German Goths

WHERE: Stretched from northern England to North Africa, Europe’s Atlantic coast to the Middle East

WHAT: Visions of a united Europe have often been anchored in the time when toga-wearing emperors spread their influence across territory even greater than today’s EU.

The EU’s founding Treaty of Rome of 1957 was signed in a city that was the seat of European civilisation and centralised power for a half a millenium.

Rome endured longer than any regime since, finally falling to infighting, overreach and barbarian invasions.

Charlemagne

WHEN: 768 to 814

WHERE: Eastern Europe to Western France, most of Italy

WHAT: Rome was at the heart of the European project launched by Charlemagne, king of the Franks.

Mostly based in Aachen, Germany, Charlemagne fought endless wars to unite his vast kingdom under one throne and was crowned emperor of Rome by Pope Leo III (750-816), the first since the fall of the Roman Empire.

A zealous Christian, Charlemagne imposed his faith across Europe’s feudal boundaries, instituting political reforms and an intellectual revival.

The Holy Roman Empire would endure after Charlemagne, but as a loose confederation of German duchies and city-states.

Charles V

WHEN: 1515-1555

WHERE: Spain, Italy, Germany, the Netherlands and South America.

WHAT: The one ruler of the Holy Roman Empire who sought to unite Europe into a seamless whole on scale with today’s European Union was Charles Hapsburg.

Charles V was a French-speaking Belgian with a Spanish mother and a Flemish father who tried to forge a Europe based on staunch Catholicism, common laws and colonialism.

But Europeans proved to be too disparate and unwilling to pay taxes to a Belgium-based autocrat with whom they had little in common.

Charles V stood down as monarch after ruling for 34 years, retiring to a monastery in Spain.

Napoleon Bonaparte

WHEN: 1799-1815

WHERE: Spain to the outskirts of Moscow

WHAT: The French Revolution, rooted in the Enlightenment, changed Europe forever, not least because a Corsican dictator tried to impose its values across much of what is now the EU.

Influenced by ancient Rome, Napoleon transformed the French Revolution into a family-run empire, and embarked on a decade of military battles that ended with his final defeat at Waterloo, now a Brussels suburb.

Napoleon felt deeply for Europe’s Roman past. He gave Paris a Roman-style triumphal arch to celebrate his war dead and created the Legion of Honour, an order of distinction, on the model of the Roman Legio Honoratorum. He also invoked Charlemagne at his imperial coronation in 1804.

Victor Hugo

WHEN: 1840s

WHAT: After the Congress of Vienna, the post-Napoleonic peace deal, Europe became a continent of nation states that worked warily together in a careful balance of power operated by political conservatives.

Against this, intellectuals such as France’s Victor Hugo and Italy’s Giuseppe Mazzini pleaded for a united states of Europe based on peace and a leftist common purpose that would fuel the revolutions of 1848 - and provide the basis for visions of post-Second World War Europe.

Adolf Hitler

WHEN: 1938-1945

WHERE: Most of Europe, parts of North Africa and Russia

WHAT: Hitler’s vision of Europe under the Nazi swastika was less a dream than a twisted search for “lebensraum” for a Greater Germany.

Rome again proved an inspiration, in the form of the Nazi eagle and other martial iconography, as well as Hitler’s grand architectural projects.

There were also echoes of Napoleon, particularly in that it was another doomed attempt to conquer Russia that would eventually see the 1,000-year Reich collapse within six years of war that left tens of millions dead.

Boris Johnson, now Britain’s foreign minister, sparked outrage last year when he compared the EU to Napoleon and Hitler.

European Union

WHEN: 1957 - ?

WHERE: Currently 28 nations

WHAT: In 1950, just five years after Second World War, French foreign minister Robert Schuman unveiled proposals for an economic union between France and West Germany, drawing on the ideas of economist Jean Monnet that were long seen as a pacifist fantasy.

A year later, six countries - Belgium, France, Germany, Italy, Luxembourg and The Netherlands - established the European Coal and Steel Community, from which on March 25, 1957, the Treaty of Rome established the precursor of the EU.

Britain is now set to become the first country to leave, but the EU is a chapter in Europe’s history that remains unfinished.