Everything you need to know about the Holy Roman Empire

Its name, however is rather misleading: the French philosopher Voltaire once decried the realm as “neither holy, nor Roman, nor an empire”.

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So why did it have that name?

It was not until 1254 that the title of Holy Roman Empire was applied, but the origins of the name date back to AD 800, more than 300 years after the western half of the Roman Empire had collapsed.

The Pope at that time, Leo III, was forced to flee Rome and, in desperation, he turned for help to Charlemagne, the powerful King of the Franks, who then ruled what is now roughly France and Germany. Charlemagne came to Leo’s aid.

In AD 800, the grateful Pope crowned him as Roman Emperor as a gift.

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How did the Empire develop after that?

After Charlemagne’s death in AD 814, his squabbling heirs broke up the Empire and the title of Roman Emperor became fairly meaningless for over a century.

It was revived by Otto I, King of the Eastern Franks (who ruled an area approximately equating to modern-day Germany), who had himself been crowned by Pope John XII in AD 962.

As with Charlemagne, Otto was crowned as a reward for having helped Pope John deal with his enemies in Italy.

From that point, the Empire was chiefly centred on Germany, though it retained lands in Italy and elsewhere in central Europe.

What relationship did these latter Roman Emperors have with the Popes?

The Empire, having been created and reinforced by the papacy at times of trouble, enjoyed a complex and frequently difficult relationship with the bishops of Rome.

The years after Otto’s reign were a high point for the Empire – at that time the most powerful in Europe – and a low one for the papacy.

A series of Roman Emperors took their title seriously and sought to dominate the Popes, even deposing those they didn’t approve of.

By the mid 11-th century, however, the papacy was recovering and gaining power.

In 1075, a lengthy battle for dominance between the Popes and Emperors, known as the Investiture Conflict, began.

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The death in 1250 of Emperor Frederick II, following a failed campaign in Italy, marked the final defeat of the Empire in this clash.

From then on, the link between the Popes and Emperors was largely broken.

Though the Empire kept its title, it was greatly weakened, particularly as it took 23 years to settle the decision of who should succeed Frederick – the most extraordinary, intelligent and ambitious of the Emperors.

No longer seeking European domination, the Empire settled into a loose confederation of mainly German states, with the Emperor often marginalised.

How did the Empire come to an end?

It was the French ruler Napoleon Bonaparte who oversaw the events that brought about the end of the Holy Roman Empire.

Having declared himself heir to Charlemagne, Bonaparte aimed to add German lands to his growing empire.

Seeing the writing on the wall, the last Holy Roman Emperor, Francis II, disbanded his realm in 1806.

How was the Empire able to survive for so long?

This may perhaps be because it didn’t have much power as a single, authoritative domain.

It eventually came to comprise hundreds of territories, each of which enjoyed plenty of autonomy.

For the rulers of many of these lands, the Empire offered a welcome alternative to a dominant or even tyrannical central power.

Moreover, until the 19th century, concepts of nationalism were far less prevalent that they would go on to become, so there was little drive to unify the various German territories into one nation state.

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What was the legacy of the Holy Roman Empire?

When the German territories were unified as one country in 1871, it became known as the Reich (‘empire’ or ‘realm’). From 1933 to 1945, the Nazis sought to continue the Empire’s legacy by presiding over the Third Reich, which Adolf Hitler claimed would last 1,000 years.

More recently, the idea of the later Holy Roman Empire has been reflected in the European union where, once again, a group of disparate countries has been brought together under a loose umbrella.

This article was first published in the April 2015 issue of BBC History Revealed magazine