Long before the castellum was built in the 4th century, a Roman bridge crossed the Meuse at Maastricht, marking the site as an important river crossing at least since the time of the Gallic Wars between 58 and 50 BCE.
Before the bridge’s initial construction in the mid 1st century CE, the river could be crossed on foot or by a temporary boat bridge at the shallow pebble banks near the mouth of the Jeker River. However, seasonal floods often made this route impassable, which likely encouraged the construction of a permanent bridge with stone piers and a wooden roadway.
This bridge became increasingly important as the region grew in administrative and economic significance following Marcus Agrippa’s organisation of the Gallic provinces and the establishment of the Via Belgica from 20 BCE. Although timber remains from the first half of the 1st century CE form the earliest secure evidence of the Maastricht bridge, it may have been linked to this earlier, wider programme of road building.
By the 4th century, during the military reorganisation following the crises of the 3rd century, the river crossing and the Via Belgica were essential for supplying troops both locally and along the Rhine frontier.