The Bicol region was known as Ibalong, variously interpreted to derive form ibalio, "to bring to the other side"; ibalon, "people from the other side" or "people who are hospitable and give visitors gifts to bring home"; or as a corruption of Gibal-ong, a sitio of Magallanes, Sorsogon where the Spaniards first landed in 1567. The Bicol River was first mentioned in Spanish documents in 1572. The region was also called Los Camarines after the huts found by the Spaniards in Camalig, Albay. No prehistoric animal fossils have been discovered in Bicol and the peopling of the region remains obscure. The Aeta from Camarines Sur to Sorsogon strongly suggest that aborigines lived there long ago, but earliest evidence is of middle to late Neolithic life.
A barangay (village) system was in existence by 1569. Records show no sign of Islamic rule nor any authority surpassing the datu (chieftain). Precolonial leadership was based on strength, courage, and intelligence. The native seemed apolitical. Thus the datu's influence mattered most during crises like wars. Otherwise, early Bicol society remained family centered, and the leader was the head of the family.
The Spanish influence in Bicol resulted mainly from the efforts of Augustinian and Franciscan Spanish missionaries. The first churches in Bicol, the San Francisco Church, and the Naga Cathedral, both in Naga, along with the Holy Cross Parish in Nabua, Camarines Sur, are instituted by the Holy Order of the Franciscans. One of the oldest dioceses in the Philippines, the Archdiocese of Caceres, was also instituted in the Bicol Region. During this time, Bicol was dotted by many astilleros (shipyards) which were focused on constructing Manila Galleons from the local hardwood forests.