Final answer:
Napoleon achieved power in France through a coup d'etat and establishing himself as Consul for Life, later crowning himself Emperor of France.
Step-by-step explanation:
Napoleon achieved power in France through a series of political and military successes. In 1799, he took part in a coup d'etat that overthrew the existing government and established the Consulate. Napoleon quickly rose to dominance within the Consulate and declared himself Consul for Life in 1802. Two years later, he crowned himself Emperor of France. Through his military conquests and clever political maneuvers, Napoleon expanded his power and established an empire that spanned much of continental Europe.