I will first admit I am not expert at all in uniform identification, so I can't tell you his rank. But I do know he is/was a soldier in Napoleon's military, the conquests of which mark one of the most successful Empire expansions in all history. Those men plundered art and history's elements as they expanded Napoleon's Empire. We see the spoils of that expansion each time we enter the Louvre, which for me numbers now in the 100s. No matter where you fall on the morality of the Little General's conquest and ambition, you can perhaps agree that the artistic bent of Napoleon gave us a localized richness unparalleled in the world. He remains a hero in France, and achieved a lasting position in the history of the world. This soldier lived or died, we know not, but in service of Napoleon's ambition.
Very good to excellent condition, 200+ years old, it hasn't any chips nor hairlines, (the painting in gouache on thin wafer), and the cover glass and old French wood frame present him in fine order. The miniature is unsigned. There were artists who painted uniforms ahead of time, hung around the military sites and only had to add a head to their already half-finished paintings. Enterprising! Measurements are noted directly on the photos.