Congress had no power to coin money, therefore each state developed its own currency. Congress was unable to regulate interstate and foreign commerce; some states refused to pay for goods they purchased from abroad. Congress was unable to impose taxes; it could only borrow money on credit.
Civil wars. Probably the most important single cause of Byzantium's collapse was its recurrent debilitating civil wars. Three of the worst periods of civil war and internal infighting took place during Byzantium's decline.
Because it allowed the people to trust their leader if they all supported chritianity, because then they could all relate spiritually. Hope this helped :P
