In Hungary and Czechoslovakia. The state stayed in presence until 1989 when resistance strengths solidified in constraining the administration to desert socialism. The state viewed itself as the beneficiary to the Hungarian Soviet Republic, which was framed in 1919 as the principal Communist state made after Soviet Russia.
The Aztecs were an early civilization that was originally living around rivers, steams and other water resources for food and water.
Aztecs multiplied along the time they were along the resources. In conclusion, they were also a strong civilization that lasted a while, allowing time to populate.
(I'm sorry I can't think of a 3rd but I hope I helped)
Time and services would be the answer.
The purpose of dividing the government into 3 different branches was that so one entity did not have all the power. So they basically did it to divide the power.