When the Romans came to the peninsula, more than 200 years before Christ, they divided their newly-conquered territory into two; Hispania Citerior, which roughly corresponded to modern Catalonia, and Hispania Ulterior, the rest of the peninsula.
Tarraco, present-day Tarragona, was the capital of Roman Hispania and when Emperor Augustus made the city his home in 26 BC, it was briefly the capital of the whole of the Roman Empire.
History
A guide to Catalonian History
The Roman City of Baetulo:
Baetulo dates back to the early part of the first century BC (or BCE, as it is sometimes referred) and was one of the first Roman settlements to be established in the Iberian Peninsular. Later there would be a whole line of these along the coastal road that would go as far south as Andalusia, passing by Baleo Claudio (for the salted tuna and garum) just south of Cadiz on the Atlantic coast, up to Italica, at present day Santponce, just across the Guadalquivir from Seville, the virtual bread basket of the Roman Empire.
The city was walled and originally would have been much closer to the coast. That’s difficult to imagine nowadays as the beaches of Badalona are a long way from the museum. However, everything falls into place when you remember that to the south-west, just under halfway to Barcelona, is the River Besos. Its delta in the past was much more extensive and the years of taking water from further upstream for agriculture and its ‘taming’ close to human settlements has changed the ecology of the littoral.