Its founding, during the Cantabrian Wars (29 BC-19 BC), made it a powerful symbol of Roman domination of the tribes of the Cantabri. The city was named after the reigning emperor Augustus and his adopted family name, the gens Julia, with the Celtic toponym element "-briga", common in Iberia. Due to its strategic location in the Besaya valley, it was able to control trade between the Douro river and the Bay of Biscay. Juliobriga grew slowly, reaching its peak between the end of the 1st century and the early 2nd century AD. Following that, its population began to decline, until the city was completely abandoned in the 3rd century.