What does decentrilization mean?

How did romans count years bc? Was Baghdad involved in the Crusades? What a history of sandals and flat shoes. And where can I buy them? What are some more advantages to the wheel invention? Why are cold baths good? Whose power increased after the fall of the Roman Empire? What are the three different chronologically Approaches to storing managing and retrieving data? Who took power by disobeying the roman senate and marching his army across the Rubicon river? Why is July called July? Who brought zero to the attention to the western world? What four diseases that shorten the life span of individuals in the middle ages? Which city was burned down by a cow? WHAT is the correct order of events from earliest to most recent? How many centuries in half a millennium? Name of the longest canal in the western hemisphere? What was a long term affect of the crusades? Which European power took the spice trade from the Arabs? Why did the nomads have a hard life? What did they use as contraception in 1910? How did a peasant become a peasant in the middle ages?