It was primarily "a. Baron de Montesquieu" who James Madison borrowed the idea of separation of powers from, since this idea was one of Montesquieu's main ways of ensuring that tyrannical governments did not form.
Yes they are on the upper and lower half's of the world
Groups such as the Visigoths, Vandals, Angles, Saxons, Franks, Ostrogoths were tribes of people that helped bring about the collapse of rome.
To cause a liberal revolution in Libson in1820.