Indigenous peoples inhabited this area for thousands of years. Pre-Columbian society in the region which is now Paraguay consisted of semi-nomadic tribes at the time of Spanish encounter. They were known for their warrior traditions. These indigenous tribes belonged to five distinct language families, which was the basis of their major divisions. Differing language groups were generally competitive over resources and territories. They were further divided into tribes by speaking languages in branches of these families. Today 17 separate ethnolinguistic groups remain.
The first Europeans in the area were Spanish explorers in 1516.[10] The Spanish explorer Juan de Salazar de Espinosa founded the settlement of Asunción on 15 August 1537. The city eventually became the center of a Spanish colonial province of Paraguay, an attempt to create an autonomous Christian Indian nation.[11] This was the center of the Jesuit missions and settlements in this part of South America in the eighteenth century, which included portions of Uruguay, Argentina, and Brazil. They developed Jesuit Reductions to bring Indian populations together at Spanish missions and protect them from virtual slavery by Spanish settlers, in addition to seeking their conversion to Christianity. Catholicism in Paraguay was influenced by the indigenous peoples; the syncretic religion has absorbed native elements. The reducciones flourished in Eastern Paraguay for about 150 years, until the expulsion of the Jesuits by the Spanish Crown in 1767. The ruins of two 18th-century missions have been designated as World Heritage Sites by UNESCO