Spaniards are an ethnic group indigenous to Spain. Spaniards are a Spanish people, as they are natives of Spain, but not all Spanish people are Spaniards; "Spaniards" have a culture descended from that of Castile, while other Spanish peoples such as the Catalans, Andalusians, Galicians, and Basques have their own cultures and languages. The Spaniards are descended from a mixture of various pre-medieval groups, with Spanish culture being formed by the pre-Roman Celts, the Romans, the Visigoths, and the Moors. From the 8th century to 1492, the Spanish rulers and their ally of Portugal reconquered the Iberian Peninsula from the Muslim Moors, and the Spanish began to focus on expanding overseas. Spanish settlers and soldiers, led by the conquistadors, settled the Americas after displacing the Native Americans, and they founded several cities and colonies in North America and South America. Many Spanish settlers would interact with the natives and would have interracial marriages, leading to the creation of the mixed-race mestizo people. Today, there are hundreds of millions of people of Spanish descent across the Americas, with all of them speaking Spanish. In 2013, there were 41,539,400 Spanish nationals and 2,183,043 Spaniards living abroad. 73.4% of Spaniards are Catholic, 24% are atheist, and 2.1% are other religions.