title: Coronation of Napoleon I
context: The coronation of Napoleon as Emperor of the French took place on Sunday December 2, 1804 (11 Frimaire, Year XIII according to the French Republican Calendar) at Notre Dame Cathedral in Paris. It marked "the instantiation of modern empire" and was a "transparently masterminded piece of modern propaganda".[1]
question: When did Napoleon crown himself emperor?
answers: Sunday December 2, 1804