The art in the Grotte Chauvet is thought to be around 30,000 years old.
In the image above we see a symbol which represents a person tied, in other words, a prisoner. Perhaps prisoners were kept at that point in the cave.
Image Credit: Chauvet, J.-M., © Ministère de la culture et de la communication, Direction régionale des affaires culturelles Rhône-Alpes: Brunel-Deschamps, E. and Hillaire, C.: La Grotte Chauvet à Vallon-Pont-d’Arc. Paris, Le Seuil, 1995, p. 76. From: http://www.bradshawfoundation.com