The Continental System was a decree ordering a blockade to stop trade and communication between Great Britain and other European nations. This system was supposed to enable continental Europe to be more self-sufficient. Napoleon created it to destroy Britain's commercial and industrial economy. But, unfortunately to Napoleon, his blockade didn't stand. British smugglers were able to bring cargo into Europe and even Napoleon's allies didn't like the idea of this Continental System. The British made a blockade of their own which resulted in war and inconvenience. In conclusion, the Continental System was a downfall for France's economy.
The Peninsular war in 1808 was when Napoleon made his second mistake. Because Portugal was ignoring the Continental System, he sent an army to capture and invade Portugal. When Spanish towns rioted in protest, Napoleon deposed the Spanish King and had his brother Joseph take the throne. The Spanish people protested and caused their naturalistic feelings to become enraged, since they remained fiercely loyal to their former monarch.
The third of Napoleon's mistakes was the invasion of Russia. There were multiple reasons why Napoleon invaded Russia. First, Russia czar refused to stop selling grain to Britain and the French and Russian leaders suspected one another of having competing designs on Poland. For these reasons, Napoleon decided to invade Russia. As the French attacked, Russian soldiers retreated and started to burn grain fields and slaughter livestock so the French could have nothing to eat. In 1812 the Russian and French armies collided and after many months the Russians retreated once more. Napoleon took over Moscow but when he got there it was in flames, due to the Russians. The French retreated and the Russian troops attacked the helpless French army. After all this, Napoleon only had 10,000 soldiers remaining.