Wellington is the name most associated with the defeat of Napoleon, but it was Clemens von Metternich whom Bonaparte said "destroyed me systematically." Metternich directed the foreign affairs of the Austrian Empire through the end of the Napoleonic Wars and was the chief architect of the Congress System that followed, dominating European affairs until the upheavals of 1848.
Long denigrated as a repressive reactionary, Metternich's achievement can be appreciated by comparing the results of the Congress of Vienna to the consequences of the Treaty of Versailles or the Yalta agreement. His fear of revolution, far from being baseless paranoia, can only be seen as prophetic after the horrors of the twentieth century.
Seward's popular biography does an excellent job of describing Metternich's career without getting too entangled in political minutia. Unfortunately, the personality of Metternich is not presented as vividly as his policy.