The proclamation of Archduke Maximilian of Habsburg as Emperor of Mexico marked a significant moment during the French intervention in Mexico from 1861 to 1867. This intervention was initiated by French Emperor Napoleon III, aiming to establish a French empire in Latin America during a time when Mexico was embroiled in instability following years of conflict, including the Mexican-American War and the Reform War. The conservative elements within Mexican society, disillusioned with the liberal policies of President Benito Juárez, sought foreign support for a monarchical regime, leading to the proposal of Maximilian, a member of the Austrian royal family.

On April 10, 1864, Maximilian was formally proclaimed emperor in Queretaro, where he took the oath of loyalty to an assembled audience, including Mexican conservatives and French representatives. He proclaimed his intent to unite the country and bring European influences that could modernize Mexico. Maximilian was accompanied by his wife, Empress Carlota, who played an active role in his court and governance aspirations.

Though initially celebrated by some factions, Maximilian's reign faced numerous challenges. His government struggled against ongoing resistance from Juárez's republicans and was heavily reliant on French military support. As the U.S. Civil War ended in 1865, the United States began opposing French involvement, and by 1866, French forces withdrew. With their departure in 1867, Maximilian's reign effectively came to an end, leading to his capture and execution later that year, marking the failure of foreign intervention in Mexican politics.