What were new ways of managing the environment during the late first millennium? How did societies exploit new resources and colonize new lands?
How did geography impede the diffusion of culture and crops in sub-Saharan Africa and the Americas?
What factors contributed to the flourishing of South American and Mesoamerican cultures and states?
How did Buddhism and Hinduism spread through Southeast Asia? Why did the Khmer kingdom adopt Buddhism in place of Hinduism?