Answer:
because it represented a natural expression of his ambition
Step-by-step explanation:
In psychology, natural expression refers to concrete action or behavior that we do in order to show the desire in our heart.
We can see this in Napoleon's action.
Napoleon was known among his peers for his deep desire for power. He often initiate conquests to other territory in order to expand the power of his military,. Establishing Bonapartist dynasty was a natural expression that Napoleon took to strengthen his political power in Europe.