 After the end of the Napoleonic Wars, during which France directly or indirectly controlled much of Europe except for Russia, and the Holy Roman Empire was dissolved, the Concert of Europe tried to maintain the balance of power.The territorial boundaries agreed to by the victorious Great Powers (Prussia, Austria, Russia and Great Britain) at the Congress of Vienna in 1815 were maintained, and even more important there was an acceptance of the theme of balance with no major aggression.Otherwise the Congress system says historian Roy Bridge, "failed" by 1823.