The four main counties involved in the Congress of Vienna were Britain, Russia, Austria, and France. The spokesmen from each country are Lord Castlereagh from Britain, Alexander I from Russia, Klemens von Metternich from Austria, and Charles de Talleyrand from France.
The main reason that the Congress of Vienna was put together was to restore peace and order to Europe. One way they did this was by removing rulers who were put in power by Napoleon and restored the Monarchy. Another way it restored Europe was that it maintained the balance of power.