The Napoleonic era was an era in the history of Europe, defined by the figure of Napoléon Bonaparte. It included the late 18th and early 19th centuries. (TNG: "Hide And Q")
In 2364, Q transported William T. Riker and several other members of the USS Enterprise-D crew to a barren planet and made them play a game featuring elements from the Napoleonic Era. Data identified the era through Napoleonic equipment such as a campaign headquarters tent, and the uniform of a French Army marshal. (TNG: "Hide And Q")