The Wall of Severus is believed to be a defensive fortification built by the Roman Emperor Septimius Severus (reigned AD 193–211) during his military campaigns in northern Britannia in the early 3rd century. Although the structure is mentioned in several classical texts, its precise locations is academically disputed due to inconsistencies between sources. Scholarly consensus believes they are most likely referring to the Antonine Wall. However, Hadrian's Wall and Offa's Dyke have both been suggested as possible candidates. Archaeological evidence has been discovered showing parts of Offa's Dyke, on the England-Wales border, is at least as old as the mid 5th century, predating the 8th-century reign of the Saxon King Offa of Mercia by 300 years.