The name of Portugal derives from the joined Romano-Celtic name Portus Cale.
The region was settled by Pre-Celts and Celts, giving origin to peoples like the Gallaeci, Lusitanians, Celtici and Cynetes, visited by Phoenicians, Ancient Greeks and Carthaginians, incorporated in the Roman Republic dominions as Lusitania and part of Gallaecia, after 45 BC until 298 AD.
Rome sent numerous legions and its best generals to Lusitania to quell the rebellion, but to no avail—the Lusitanians kept conquering territory.
It was believed by some scholars that early in the first millennium BC, several waves of Celts invaded Portugal from Central Europe and inter-married with the local populations, forming different tribes.
After the Battle of São Mamede, where Portuguese forces led by Afonso Henriques defeated forces led by his mother, Theresa of Portugal, the County of Portugal affirmed its sovereignty and Afonso Henriques styled himself Prince of Portugal.
He would later be proclaimed King of Portugal at the Battle of Ourique in 1139 and was recognised as such by neighbouring kingdoms in 1143.
Democracy was restored after the Carnation Revolution in 1974, ending the Portuguese Colonial War.
Shortly after, independence was granted to almost all its overseas territories.