Old Quechuan is an extinct language that was spoken by the INCA people of South America. It is also known as Runasimi or Quechua and is believed to have been the language of the INCA Empire. The term 'Old Quechuan' refers to the earliest form of the language, which was used before the Spanish conquest of the INCA Empire in the 16th century. The INCA were a powerful civilization that ruled much of South America from the 12th to the 16th centuries.