Early Peruvian refers to the pre-Columbian civilizations of Peru, which were mainly the INCA and their predecessors. The INCA were the largest and most powerful of these civilizations, and they ruled from the 13th century until the Spanish conquest in the 16th century. The INCA Empire was known for its advanced engineering and architecture, as well as its complex social and political structure. The INCA are also remembered for their impressive road system, which connected the empire from north to south.