The earliest reference to the city “Dispargum”, now the city of Duisburg, is found in the 6th century in the ten volume history of the Franks by historian Gregor von Tours (around 539-594). According to these texts, a royal residence was located here as early as the 5th century. Archaeological finds from the following centuries document dwellings, and trade, at this location. There is a report, in a chronicle written by the monk Regino von Prüm, of an attack by the Vikings in the year 883 on the city then called “Diusburch”, which during this time belonged to the monastery Prüm in der Eifel. The essentially peaceful “Norsemen” from Denmark this time came with the intent to loot the area, plundered the settlement, and burned the houses to the ground. They established their winter camp nearby and travelled back to the coast along the Lower Rhine the following spring.

In another report from the year 893, a reference is made to Frisians in “Diusburch”. There were, during this time, successful merchants along the Rhine and in the coastal areas along the North Sea. Evidently, an important merchant settlement already existed with a port on the Rhine next to the royal court, which was developed into a prestigious fortified palace in the 10th century. In 929, the Reich’s synod took place under King Henry I. Numerous stays by kings and queens in Duisburg are documented over the next several decades.

Thanks to its location at the crossroads of waterways and roads, in particular the Rhine and the “Hellweg”, Duisburg developed into a trading hub in the Middle Ages. Foreign merchants and traders came from Scandinavia, the Baltic States, from England, Holland, Flanders, the Maasgebiet, Middle Germany, and Westphalia, and did business with merchants from the Rhineland. Duisburg’s far-reaching trade relationships in the 11th Century are evidenced by the discovery of coins, namely the Duisburg silver penny, throughout all of Europe. Coins from the Duisburg royal mint were found in Poland, Estonia, and on Bornholm. Many of these coins, most of which bore the image and name of the king on the front side, displayed images of houses, fortified walls, a church, or a fortified tower, i.e. a type of city skyline on the reverse.

The old fortifications surrounding the palatinate settlement were expanded for the protection of the growing trading city. First references of a city wall were found in the contemporary writings around 1120/25; expansions came later. In the 14th century, construction work on the city fortifications was completed. In the northeastern city centre impressive fragments of the wall have been preserved: sections of the Springwall and parts in the inner harbour. The wall also enclosed the castle square and the merchant’s quarter, today’s Stapelviertel. Archaeological excavations at the Old Marketplace have revealed numerous traces of an active market life left by people, animals and vehicles.

In 1173, Emperor Frederick I, also known as Barbarossa, established two fourteen-day long fairs in Duisburg, in order to encourage ocean-going vessels to again trade on the Rhine. The textile trade was of great importance. The trade goods also included spices, stockfish, salt, wine, beer, honey, waxes, urs, mill stones and metal hollow-ware; maybe even weapons and slaves. However, the Rhine harbour of Duisburg dried up in the latter part of the 14th century; the city lost its special significance as a place of trade, which can seen even today from the remains of the city wall, and remained a secondary, rural town until the 19th century.