before, because of the absence of 2,000 staff members of the Prefecture and military. However, the city remained the seat of a governor and had state factories for the production of ballistae and armor, and a wool mill for uniforms for the troops, clothing for the civil service and high-quality garments for the Court. Northern Gaul was held by the Romans along a line from north of Cologne to the coast at Boulogne through what is today southern Belgium until 460. South of this line, Roman control was firm, as evidenced by the continuing operation of the imperial arms factory at Amiens.
The Franks seized Trier from Roman administration in 459 AD. In 870, it became part of Eastern Francia, which developed into the Holy Roman Empire. Relics of Saint Matthias brought to the city initiated widespread pilgrimages. The bishops of the city grew increasingly powerful and the Archbishopric of Trier was recognized as an electorate of the empire, one of the most powerful states of Germany. The University of Trier was founded in the city in 1473.
In the 17th century, the Archbishops and Prince-Electors of Trier relocated their residences to Philippsburg Castle in Ehrenbreitstein, near Koblenz. A session of the Reichstag was held in Trier in 1512, during which the demarcation of the Imperial Circles was definitively established.
In the 17th and 18th centuries, Trier was sought after by France, who invaded during the Thirty Years' War, the War of the Grand Alliance, the War of the Spanish Succession, and the War of the Polish Succession. France succeeded in finally claiming Trier in 1794 during the French Revolutionary Wars, and the electoral archbishopric was dissolved. After the Napoleonic Wars ended in 1815, Trier passed to the Kingdom of Prussia. Karl Marx was born in the city in 1818.
As part of the Prussian Rhineland, Trier developed economically during the 19th century. The city rose in revolt during the revolutions of 1848 in the German states,
