This is called distress (the opposite, eustress, is the opposite).
They were a very complex and highly technologically advanced people.
The answer is separation or in other terms split. The separation or split likely occur because of the fact that the byzantines rejected the pope's authority, where in they don't agree with his ways or doing things and his authorization. That led the byzantines to be separated where in they no longer want to be involve with the pope and their people.
The U.S used the Texas-Mexico border dispute to annex Texas as a state and gain more land from Mexico. Basically all the land that Mexico owned in North America was given to the U.S after the U.S defeated Mexico in the war.
Answer:
The plains tend to be very easy for early settlements to bring about agriculture, mobility, and mild weather conditions that helps early civilization grow. The negative impact of most plains come from it's lack of ability to trade easily in later generations, without water access
