Napoleon didn't tear down the ancien regime, he was still a very junior officer when that happened. If anything he turned a Republic back into an Empire.
He overthrew many monarchies in Europe, and installed French civil system to the newly occupied regions. Although he did assign his relatives to be monarchies in those areas, the reforms are real and the difference weren't felt until he was defeat and old monarchies came back. His military conscriptions certainly offset his reforms in popularity. Italians vied for independence from Austrian Empire after Napoleon was defeated. Interestingly, it was Napoleon III (Napoleon I's naphew) who helped eventually Italian won independence.
http://en.wikipedia.org/wiki/Second_Italian_War_of_Independe...