Instability was from the Treaty of Versailles left many countries bitter for they did not get fully compensated for the war. Germany, especially, experienced economic and political issues bc they had to be a republic and pay billions in reparations. Russia was faced with a revolution and struggled with famine and inflation. Europe was faced with even more instability after the stock market crash of 1930.
The division of the Roman Empire into eastern and western halves was a crucial step in the formation of the "Byzantine Empire", since this Empire "grew" in many ways from the former.
