During the Neolithic period, the region was inhabited by Pre-Celtic tribes, who built religious and funerary monuments, megaliths, dolmens and menhirs, which still survive in areas on the periphery of Lisbon.
The Indo-European Celts invaded in the 1st millennium BC, mixing with the Pre-Indo-European population, thus giving rise to Celtic-speaking local tribes such as the Cempsi.
Although the first fortifications on Lisbon's Castelo hill are known to be no older than the 2nd century BC, recent archaeological finds have shown that Iron Age people occupied the site from the 8th to 6th centuries BC.
During this period, he organised the tribes of Lusitania and Hispania and was on the verge of forming an independent province in the Sertorian War when he was assassinated.Unlike most capital cities, Lisbon's status as the capital of Portugal has never been granted or confirmed officially – by statute or in written form.Its position as the capital has formed through constitutional convention, making its position as de facto capital a part of the Constitution of Portugal.Olissipo, like most great cities in the Western Empire, was a centre for the dissemination of Christianity. 356), and there were several martyrs during the period of persecution of the Christians: Maxima, Verissimus and Eulalia of Mérida are the most significant examples.By the time of the Fall of Rome, Olissipo had become a notable Christian centre.The westernmost areas of its metro area form the westernmost point of Continental Europe, which is known as Cabo da Roca, located in the Sintra Mountains Lisbon is recognised as a alpha-level global city by the Globalization and World Cities (Ga WC) Study Group because of its importance in finance, commerce, media, entertainment, arts, international trade, education and tourism.It is also the political centre of the country, as its seat of Government and residence of the Head of State.One claim often repeated in non-academic literature is that the name of Lisbon can be traced back to Phoenician times, usually referring to the supposed Phoenician term Alis-Ubo, meaning "safe harbour".Lisbon's origin may in fact derive from Proto-Celtic or Celtic Olisippo, Lissoppo or a similar name which other visiting peoples like the Ancient Phoenicians, Greeks and Romans adapted accordingly.Many of these ruins were first unearthed during the mid-18th century (when the recent discovery of Pompeii made Roman archaeology fashionable among Europe's upper classes).The city prospered as piracy was eliminated and technological advances were introduced, consequently Felicitas Julia became a centre of trade with the Roman provinces of Britannia (particularly Cornwall) and the Rhine.