Astorga was originally a Celtic settlement which later become one of the Roman strongholds in the region they called Asturica. The Roman city was founded in 14 BC, being entitled by Emperor Octavian as Asturica Augusta. Ruins of Roman baths are still visible today.
The walls of the town were built at the time of Ancient Rome.
Asturica was the main city in north-west Spain during the Roman Empire. Plinius called the city Urbs magnifica ("magnificent city"). The Via Platea went from Asturica (Astorga) to Emerita (Mérida). One of the first three bishoprics in Spain was founded in Astorga, so the title of Bishop of Astorga is one of the oldest religious charges of Europe.