Anthropology

Measles traveled faster so liely weakened them before smallpox arrived. Europeans didn't conquer the Americas, viruses did.

Otherwise, anacyclosis was taking shape in the Incan Empire, a dictator ruled at the pleasure of a power elite, a clear sign that decline had begun. In addition, empires are always surrounded by hostile forces who look at the way a predator class impoverishes the people who do the actual work and decide they want no part of that. The Spaniards had help, IOW, lots of it.

The fact that smallpox disproportionately wiped out the ruling class is new to me and the opposite of what happened in Europe when waves of disease swept through every 20-30 years. Smallpox was 30% fatal in Europe, significantly lower but still devastating.

Thanks for another piece of the puzzle. I knew PIzarro had significant help from neighboring tribes. I hadn't known just how targeted smallpox and measles had been. Likely they would have spread to the population at large given enough time. Pizarro stopped that clock for a while.