There are various theories about the origin of the word ''Chile''. According to 17th-century Spanish chronicler Diego de Rosales, the Incas called the valley of the Aconcagua ''Chili'' by corruption of the name of a Picunche tribal chief () called ''Tili'', who ruled the area at the time of the Incan conquest in the 15th century. Another theory points to the similarity of the valley of the Aconcagua with that of the Casma Valley in Peru, where there was a town and valley named ''Chili''.