Anatomically modern humans first arrived in the Iberian Peninsula around 42,000 years ago. Pre-Roman peoples dwelled in the territory, in addition to the development of coastal trading colonies by Phoenicians and Ancient Greeks and the brief Carthaginian rule over the Mediterranean coastline. The Roman conquest and colonization of the peninsula (Hispania) ensued, bringing a Roman acculturation of the population. Hispania remained under Roman rule until the collapse of the Western Roman Empire in the fourth century, which ushered in the migration of Germanic peoples and the Alans into the peninsula. Eventually, the Visigoths emerged as the dominant power in the peninsula by the fifth century. In the early eighth century, most of the peninsula was conquered by the Umayyad Caliphate and during early Islamic rule, Al-Andalus became the dominant peninsular power, centered in Córdoba. Several Christian kingdoms emerged in Northern Iberia, chief among them León, Castile, Aragón, Portugal, and Navarre and over the next seven centuries, an intermittent southward expansion of these kingdoms, known as Reconquista, culminated with the Christian seizure of the Emirate of Granada in 1492. Jews and Muslims were forced to choose between conversion to Catholicism or expulsion and the Morisco converts were eventually expelled. The dynastic union of the Crown of Castile and the Crown of Aragon was followed by the annexation of Navarre and the 1580 incorporation of Portugal (which ended in 1640). In the wake of the Spanish colonization of the Americas after 1492, the Crown came to hold a large overseas empire, which underpinned the emergence of a global trading system primarily fuelled by the precious metals extracted in the New World. Centralisation of the administration and further State-building in mainland Spain ensued in the 18th and 19th centuries, during which the Crown saw the loss of the bulk of its American colonies a few years after of the Peninsular War. The country veered between different political regimes; monarchy and republic, and following a devastating civil war, 1936-39, a fascist dictatorship that lasted until 1975.