Lisbon is the capital and the largest city of Portugal, with an estimated population of 544,851 within its administrative limits in an area of 100.05 km2. Lisbon's urban area extends beyond the city's administrative limits with a population of around 2.7 million people, being the 11th-most populous urban area in the European Union. About 2.9 million people live in the Lisbon metropolitan area, which represents approximately 27% of the country's population.
It is mainland Europe's westernmost capital city and the only one along the Atlantic coast. Lisbon lies in the western Iberian Peninsula on the Atlantic Ocean and the River Tagus. The westernmost portions of its metro area, the Portuguese Riviera, form the westernmost point of Continental Europe, culminating at Cabo da Roca. Lisbon is one of the oldest cities in the world, and the second-oldest European capital city (after Athens), predating other modern European capitals by centuries. Julius Caesar made it a municipium called Felicitas Julia, adding to the name Olissipo. After the fall of the Roman Empire it was ruled by a series of Germanic tribes from the 5th century; later it was captured by the Moors in the 8th century. In 1147 Afonso Henriques conquered the city and since then it has been the political, economic and cultural center of Portugal.