Map of Greece

What geographic feature encourage the development of city-states?

Greece is made up of a lot of hills, and mountains that separated groups of people. Also, there is a lot of shoreline that allows for many people to be self-sufficient.

What type of military defense seemed called for by the geography of Ancient Greece?

Greece needed to have both a strong army for land battles and a strong navy to defend all the waterways in and around Greece.

Why would Athens and Sparta need to work together in order to succeed in creating a Greek Empire?