Because they were big events in history that made today be today ;)
Answer: President Dwight Eisenhower proclaimed standards for flying the American flag at half staff on March 1, 1954. Prior to this date, there were no official rules for flying the flag at half staff, which led to policies that differed from area to area.
Explanation:
I believe it was the division of Byzantium and the Latin West. Byzantium was the emperor of Constantinople the area around Greece and Turkey and North into Russia. Latin West was under the control of different people until dominance of the Franks in the region. Another powerful and well noted authority was the Pope. Basically...there was a the decline of Rome and different views on the Christian doctrine. (Q_Q ) That's the best way I can word it.
China, with most decision making power concentrated into a few members of the communist party is best described as a Oligarchy. This is the form of governance where most decision making powers lies with a powerful few and the others have to agree and obey the decision made. I hope the answer helps you.