Portrait of Maximilian I of Mexico (1832-1867)

Title: Portrait of Maximilian I of Mexico (1832-1867)
Artist: Franz Xaver Winterhalter
Date:1864

Portrait of Maximilian I of Mexico in coronation robes. At the behest of Mexican monarchists and French Emperor Napoleon III, Austrian Prince Maximilian agreed to serve as Emperor of Mexico. Original in Chapultepec Castle, Mexico City. Monarchs have often worn ceremonial robes at their coronations and investitures. The mantles of the emperors and kings are called coronation mantles. Some monarchs have taken an oath but were not crowned. Their mantles are of the same design as those of the crowned monarchs. There are also the less costly mantles that were used for other ceremonies. They are made after the fashion of the coronation mantles. Monarchs that were not crowned, petty rulers (such as Grand Dukes in Germany) and members of royal families are often depicted in this way. These ceremonial regal robes, "Prunkmäntel" in German, may be called "ceremonial regal robes" to distinguish them from the robes that were worn at coronations.

Source :
http://blog.fords.org/2014/05/05/matias-romero/emperador_maximiliano_i_de_mexico/
https://commons.wikimedia.org/wiki/Coronation_and_royal_robes

Maximilian van Oostenrijk (Maximilian I of Mexico)

Title: Maximilian van Oostenrijk
Artist: Franz Xaver Winterhalter
Date: Unknown

Maximilian (Spanish: Maximiliano; born Ferdinand Maximilian Joseph; 6 July 1832 – 19 June 1867) was the only monarch of the Second Mexican Empire. He was a younger brother of the Austrian emperor Francis Joseph I. After a distinguished career in the Austrian Navy, he entered into a scheme with Napoleon III of France to invade, conquer, and rule Mexico. France (along with the United Kingdom and Spain, who both withdrew the following year after negotiating agreements with Mexico's democratic government) had invaded Mexico in the winter of 1861, as part of the War of the French Intervention. Seeking to legitimize French rule in the Americas, Napoleon III invited Maximilian to establish a new Mexican monarchy for him. With the support of the French army, and a group of conservative Mexican monarchists hostile to the liberal administration of new Mexican President Benito Juárez, Maximilian traveled to Mexico. Once there, he declared himself Emperor of Mexico on 10 April 1864. Many foreign governments (including the United States) refused to recognize Maximilian's claim or regime. Maximilian's Second Mexican Empire was widely considered a 'puppet' regime of France. Additionally, Maximilian never completely defeated the Mexican Republic; Republican forces led by President Benito Juárez continued to be active during Maximilian's rule. With the end of the American Civil War in 1865, the United States (which had been too distracted by its own civil war to confront the European's 1861 invasion of what it considered to be its sphere-of-influence) began more explicit aid of President Juárez's forces. Matters worsened for Maximilian's 'empire' after the French withdrew its armies from Mexico in 1866. Maximilian's Mexican Empire collapsed; the Mexican government captured and executed Maximilian in 1867. His wife, Charlotte of Belgium (Carlota), had left for Europe earlier to try to build support for her husband's regime; after his execution, however, she suffered an emotional collapse and was declared insane.

Source :
https://en.wikipedia.org/wiki/Maximilian_I_of_Mexico