Portugal is the oldest state on the Iberian Peninsula and one of the oldest in Europe, its territory having been continuously settled, invaded and fought over since prehistoric times. The pre-Celtic people, Celts, Carthaginians and Romans were followed by the invasions of the Visigoths and Suebi Germanic peoples. Portugal as a country was established during the Christian Reconquista against the Moors who had invaded the Iberian Peninsula in 711 AD. Founded in 868, the County of Portugal gained independence after the Battle of São Mamede in 1128. The Kingdom of Portugal was proclaimed following the Battle of Ourique in 1139 and was recognised by the neighbouring kingdoms by the Treaty of Zamora in 1143.
Around 200 BC, the Romans took the Iberian Peninsula from the Carthaginians during the Second Punic War, and in the process conquered Cale and renamed it Portus Cale (Port of Cale) incorporating it to the province of Gaellicia with capital in Bracara Augusta (modern day Braga, Portugal). During the Middle Ages, the region around Portus Cale became known by the Suebi and Visigoths as Portucale. The name Portucale evolved into Portugale during the 7th and 8th centuries, and by the 9th century, that term was used extensively to refer to the region between the rivers Douro and Minho. By the 11th and 12th centuries, Portugale, Portugallia or Portvgalliae was already referred to as Portugal.
Several works of engineering, such as baths, temples, bridges, roads, circus, theatres and layman's homes are preserved throughout the country. Coins, some of which coined in Lusitanian land, as well as numerous pieces of ceramics were also found. Contemporary historians include Paulus Orosius (c. 375–418) and Hydatius (c. 400–469), bishop of Aquae Flaviae, who reported on the final years of the Roman rule and arrival of the Germanic tribes.
An Asturian Visigothic noble named Pelagius of Asturias in 718 was elected leader by many of the ousted Visigoth nobles. Pelagius called for the remnant of the Christian Visigothic armies to rebel against the Moors and regroup in the unconquered northern Asturian highlands, better known today as the Cantabrian Mountains, in what is today the small mountain region in North-western Spain, adjacent to the Bay of Biscay.
War led to a deterioration of the relations with Portugal's oldest ally, England, and the loss of Hormuz, a strategic trading post located between Iran and Oman. From 1595 to 1663 the Dutch-Portuguese War primarily involved the Dutch companies invading many Portuguese colonies and commercial interests in Brazil, Africa, India and the Far East, resulting in the loss of the Portuguese Indian sea trade monopoly.