His nickname of L'Aiglon ("the Eaglet") was awarded posthumously and was popularized by the Edmond Rostand play, L'Aiglon.
When Napoleon I tried to abdicate on 4 April 1814, he said that his son would rule as emperor.
However, the coalition victors refused to acknowledge his son as successor, and Napoleon I was forced to abdicate unconditionally some days later.
Although Napoleon II never actually ruled France, he was briefly the titular Emperor of the French in 1815 after the second fall of his father.