Some historians have argued that Greeks were the first to settle Cale and that the name derives from the Greek word kallis, 'beautiful', referring to the beauty of the Douro valley. Others have hypothesized that the word Cale cames from the Latin for 'warm' (Portus Cale thus meaning Warm Port). The main explanation for the name, however, is that it is a ethnonym derived from the Castro people that settled in the area of Cale - the Callaeci. Others, still, believe that the name came from the main goddess this tribe adored, which could be the same Cailleach in Ireland as Celts arrived to that island from Galicia. Hector Boece said Portugal derived from Porto Gatelli the name Gatelo gave to Braga when he settled there while others say he gave that name to PortoThe names "Callaici" and "Cale" are the origin of today's: Gaia, Galicia, and the "Gal" root in "Portugal". The meaning of Cale or "Calle" is however not fully understood.
Around 200 BCE, the Romans began to take the Iberian Peninsula from the Carthaginians during the Second Punic War, and in the process conquered Cale and renamed it Portus Cale. This was done by the general Decimus Junius Brutus Callaicus around 136 BC. At the end of Brutus' campaigns, Rome controlled the territory between the Douro and Minho rivers plus probable extensions along the coast and in the interior. It was only under Augustus, however, at the end of the 1st century BC, that present north Portugal and Galicia were fully pacified and under Roman control.
All these region would fall under Suebi dominion between 410 and 584. These Germanic invaders settled mainly in the areas of Braga (Bracara Augusta), Porto (Portus Cale), Lugo (Lucus Augusti) and Astorga (Asturica Augusta). Bracara Augusta, the modern city of Braga and former capital of Roman Gallaecia, became the capital of the Suebi.
Another Germanic people, the Visigoths, also invaded the Iberian Peninsula and would eventually conquer the Suebi kingdom in 584. The region around Cale became known by the Visigoths as Portucale. Portus Cale would fall under the Moorish Muslim invasion of the Iberian Peninsula in 711.
In 868, Vímara Peres, a Christian warlord from Gallaecia and a vassal of the King of Asturias, Léon and Galicia, Alfonso III, was sent to reconquer and secure from the Moors the area from the Minho River to the Douro River, including the city of Portus Cale, founded the First County of Portugal or Condado de Portucale. Portus Cale is thus the former name of current day Porto and Vila Nova de Gaia's riverside area, that would be used to name the whole region and, after, the country.