text: Another theory states that more and more people near and far surrounding the Empire heard about its riches, and wanted a piece. Attila the Hungarian summoned up an army of one million troops and fighters by uniting hungry tribes to fight the Roman army at Catalaneum. The fight ended in a draw, but it weakened the Empire, so much so that it could not strike back -- there were no centres of enemy concentrations, the enemy was all spread out in seemingly infinite fields, few and far between, only to concentrate when THEY wanted to attack.
  
  Another problem was the stagnant birth and growth rate by the free people, and the burgeoning population growth of the slaves. Slaves were encouraged to have children, whereas Romans were encouraged to have just two per couple. Then the Christian imperative "go forth and multiply" took over, and there was a sexual mayhem.
  
  Lastly, Christianity put a moral end to slavery. End of economic system. More and more slaves were constantly freed.