Why did it take so long for the nations of Europe to defeat Napoleon I?

Napoleon had been working hard in building a powerful and great empire ever since the beginning of his rule as Emperor in 1804. Since before that time he had managed to expand French territory into Italy, he had annexed the Austrian Netherlands, The German States, the Batavian Republic, later on he annexed parts of Egypt, and Parts of Spain. It was because of this hugely successful foreign policy and France's revolutionary background that the Nations of …showed first 75 words of 755 total…

…showed last 75 words of 755 total…ward off his enemies in battle and despite his defeats he managed to hold on to his conquered territory for longer then his enemies had expected. However, because there were so many of them against Napoleon alone, it was increasingly easy for them to surround him and tighten the circle around his empire until it was impossible for Napoleon to fight back for any longer, unfortunately that took longer then the Allies had hoped for.