Assertion: Napoleon Bonaparte crowned himself as Emperor of France in 1804.
Reason: The Directory of France allowed him to do so.

Explanation:
Napoleon Bonaparte rose to power during the French Revolution and became the First Consul of France in 1799. He was a skilled military leader and had gained popularity for his success in various military campaigns.

The Directory:
The Directory was the government that ruled France from 1795 to 1799. It was a weak and corrupt regime, marked by political instability and economic struggles. The Directory faced numerous challenges, including internal conflicts and external threats. The French people were disillusioned by the Directory's inability to address these issues effectively.

Napoleon's Rise to Power:
Taking advantage of the discontentment with the Directory, Napoleon staged a successful coup d'état on November 9, 1799 (18 Brumaire in the French Republican Calendar). This event marked the end of the Directory and the beginning of the Consulate era, with Napoleon as the First Consul.

Consulate Era:
During the Consulate era, Napoleon consolidated his power and implemented various reforms, including the centralization of government, the Napoleonic Code, and the establishment of a strong bureaucracy. He also embarked on a series of military campaigns to expand the French Empire.

Establishing the Empire:
In 1804, Napoleon decided to consolidate his power further by transforming the Consulate into an Empire. He organized a plebiscite, a direct vote in which the people express their opinion, to legitimize his decision. The plebiscite resulted in an overwhelming majority in favor of establishing an empire.

Coronation as Emperor:
On December 2, 1804, Napoleon Bonaparte crowned himself as Emperor of the French in a grand ceremony held at Notre-Dame Cathedral in Paris. This act symbolized his elevation to a higher position of power and authority. It is important to note that Napoleon did not seek approval from the Directory or any other governing body to crown himself as Emperor. He took advantage of the popular support he had gained and the weak political situation in France to assert his authority.

Conclusion:
Napoleon Bonaparte crowned himself as Emperor of France in 1804 without the explicit permission of the Directory. The Directory's weak and corrupt governance allowed Napoleon to rise to power, and he took advantage of the favorable political climate to establish himself as the Emperor.