Recent research shows that the battle of Solicinium, fought in 368 between the invading Alamanni and a Roman army led by Emperor Valentinian I, probably took place in the northern part of what is today Hechingen and the lost city Solicinium was located where the Roman museum of Hechingen is located today.

Hechingen is the ancestral home of the Hohenzollern dynasty of princes, electors, kings, and emperors, of Brandenburg, Prussia, the German Empire, and Romania.

Hechingen was located on an Imperial highway which led from the middle Neckar south by way of Rottweil to the upper Rhine and the Alpine passes.

The cost of rebuilding was so great that Friedrich XII of Hohenzollern, known as der Öttinger, sold his entire fortune to Württemberg in 1415.

Although his cousins in Brandenburg attempted arbitration for him, Henriette, Countess of Montbéliard, Duchess of Württemberg, took the castle in 1423 and destroyed it.

His brother, Eitel Friedrich IV of Hohenzollern, also pledged his allegiance to Württemberg, turning over his inheritance if he did not have an heir.

His son, Count Jos Niklaus of Hohenzollern was able to gain Imperial permission to rebuild the castle, as well as to nullify the agreement with Württemberg.

Many buildings built during his reign are still to be seen today: the convent church St. Luzen, the hospital, and the lower tower – the latter being the last remnant of the city defences.

On 3 April 1634, the castle surrendered to the Württembergs, whose soldiers plundered everything they could get their hands on, even draft animals farmers needed to plow their fields.

That year the castle fell into the hands of Maximilian I, Elector of Bavaria (1573–1651), who held it until 1637, when Hohenzollern rule was restored.

The architecture of the city was greatly influenced by the architect Pierre Michel d'Ixnard, who was a predecessor of Classicism in southern Germany.

They had famous guests, including Eugénie's cousin, the future Napoleon III, Hector Berlioz, and Franz Liszt.

After the Revolution of 1848, Constantine retired from public life, and his county passed into the control of the Protestant kingdom of Prussia in 1850.

To protect them from further destruction, many industries, including DEHOMAG, a predecessor of IBM, were relocated to Hechingen from damaged areas of Germany, such as Berlin.

[4] Many of the physicists captured there were later interned in England in Operation Epsilon and tried in German war crimes tribunals over the following years.

After the Second World War, IBM, BMW, and HP applied for building permits, which the city government denied.