The document discusses several key events in world history from different perspectives:
- A catastrophic climate event around 535 AD that caused global cooling, drought, famine and the spread of plague across Europe and Asia.
- The exploration of the Americas by Columbus seeking an alternate trade route to Asia, leading to the Columbian Exchange of crops, animals and diseases between the Old World and New World.
- The Spanish conquest of the Aztec empire led by Hernan Cortes, who allied with local groups to defeat the Aztecs and claim their gold, changing the course of history in Mesoamerica.