HW Kaufmann has an MA in Spanish from the University of Texas at San Antonio, where she also studied archaeology. She has a PhD from the University of Texas, Austin, in medieval Spanish and is fluent in six languages. She is a professor at San Antonio College and teaches languages. JE Kaufmann has an MA in History from the University of Texas, San Antonio. He is a retired public school teacher and teaches history part time at Palo Alto Junior College.

Adam Hook studied graphic design, and began his work as an illustrator in 1983. He specializes in detailed historical reconstructions, and has illustrated Osprey titles on the Aztecs, the Greeks, the American Civil War and the American Revolution. His work features in exhibitions and publications throughout the world. He lives in East Sussex.

The greatest period of Inca expansion occured during the reigns of Pachacuti (1438-71), Tupa Inca (1471-93), and Huayna Capac (1493-1527). From the mountain stronghold of Cuzco, they subjugated the surrounding kingdoms and territories, absorbing their civilizations and their peoples. By 1525, they dominated much of the west of the continent, relying on fortified strongholds, an extensive system of roads and bridges, and obligatory military service to control local populations. This title takes a detailed look at the development of Incan fortification techniques, and examines how they came to be overrun by the Spanish conquistadors.