Napoleon wanted his empire to last for centuries. He started by trying to build up a navy to defeat the British, but the British won a decisive naval victory at the Strait of Gibraltar. He then imposed the Continental System, which failed miserably. After Russia had opposed the Continental System, it left him no choice but to invade. After the Russian troops had retreated for hundreds of miles, they finally fought. The French won, but only returned to Poland with 40,000 out of the 600,000 they brought. After seeing the crippled French Army, other countries took advantage and attack. Paris was captured in March of 1814, and the monarchy was restored.