The history of Weißenburg is generally traced back to the Roman fort that was built in the area towards the end of the first century. The settlement, which included Thermae, lay on the border of the Roman Empire and on the Tabula Peutingeriana from the 4th century it had the name Biriciana. Germanic tribes destroyed the fort and settled in what is still the city centre. The first mention of the name Weißenburg is in a deed dating from 867. The city became the seat of a royal residence during the reign of the Franks and according to legend, Charlemagne stayed there to supervise the construction of Fossa Carolina.