Lisbon’s history as a human settlement dates back to the Neolithic period when the region was inhabited by Pre-Celtic tribes who built all manner of religious and funerary monuments in the area before being invaded by the Indo-European Celts. By 1200 BCE it’s believed a Phoenician trading post might have been present on the southern slope of the Castle hill, as the sheltered harbor below was ideal for providing a secure port to provision their ships travelling on to the modern day Isles of Scilly and Cornwall. It might even have been called Allis UbboPhoenician for “safe harbor” – if the toponymy for the origin of Lisbon is correct. However an alternate theory suggests the settlement was in fact one of the earliest ancient Roman states, that at most maintained commercial relations with the Phoenicians having been an important commercial centre for trade with inland tribes and the sale of the renowned Lusitanian horses. Written in Latin as Ulyssippo, legend held that the region had in fact been named for Ulysses who founded the settlement after he left Troy to escape the Greek coalition.

With the defeat of Hannibal during the Punic wars, the Roman Empire moved to deprive Carthage of its control over the Iberian Peninsula and with their defeat by Scipio Africanus in the east, the Romans were able to pacify the west. It was during this that Ulyssippo allied with the legions against the northwestern tribes and earned their right to self-rule as a municipium, enjoying full rights as Roman citizens. During this period Lusitanian raids and rebellions necessitated the construction of a wall around Ulyssippo, but during the reign of Augustus also saw a great theatre, baths, necropolis, and numerous temples to their gods and the Emperor built. As piracy was eliminated, and various technological advances were introduced, the municipium became the centre of trade with the Roman provinces of Britannia and the Rhine.