<span>They started because the Persian Empire expanded into Ionia where there were several Greek colonies. The colonists sent back to Greece for help. The Athenians sent a few ships to help the colonists, but the cities were taken any way. To put the mainland Greeks in their place, the Persians sent a small force to punish the Greeks. So begins the battle of Marathon. </span>
the effects were that people who lived in the hotter parts were more suited and were used as slaves and workers. Also the people that were less suited to the heat were kept indoors. In most cases the only people who had less possibilities in the sun were rulers and upper class.
Support of one section without regard to other sections or the nation as a whole is called sectionalism
