What was the porpoise of the congress of Vienna?

The Congress of Vienna came about due to the European powers' territorial ambitions as well as Napoleon's final defeat at Waterloo.

For the first reason, the congress intended on guaranteeing international tranquility to balance powers. The guiding principle in this congress was that no country should be powerful enough to destabilize international relations.

For the second reason, something had to be done with France. There was no existing government in France. The Congress of Vienna then put Louis XVIII on the throne instead.

These were the two major reasons for the Congress of Vienna.