The Inca Empire of South America lasted just over 100 years. But in that short span, the Incas conquered an area almost as vast as the Roman Empire. In this podcast, Terence D'Altroy of Columbia University describes why the Incas were so successful.

Podcast produced and edited by David Levin. Interview by Peter Tyson. NOVA is produced by WGBH in Boston. Funding for NOVA is provided by ExxonMobil, David H. Koch, the Howard Hughes Medical Institute, the Corporation for Public Broadcasting, and public television viewers.

To learn more, visit www.pbs.org/nova/inca