The Continental System was a decree that Napoleon signed stating that all trade and communication between Great Britain and any other European nations was not allowed. Unfortunately Napoleon's blockade was not strong enough smugglers managed to bring cargo from Britain to Europe.
The Peninsular Campaign was when Napoleon got rid of the King of Spain and put his brother on the throne. It failed because the Spanish were upset about it so the fought the French and added on more to the French problems.
The Invasion of Russia was when the alliance between France and Russia broke down. Because of this Napoleon decided to invade Russia. Because of Napoleon's invasion more wars came and in the end the Russians retreated causing Napoleon to stay in a town that was burnt to the ground. When he realized no one was coming to make a peace offer he retreated in the middle of October and most of his army died.