Jacques-Louis David is a famous painter of the late XVIII and beginning of XIX centuries, master of portraits, historical paintings, and mythological scenes.
In my corralling of horse images from the annales of history and art, two works of monsieur David come to shine.
Chronologically, the portrait of our Polish aristocrat Stanisław Kostka Potocki and then the more famous one, being the image of a man who shaped the modern Europe, l'empereur of the French, Napoleon Bonaparte.
The equestrian portrait of Potocki, Pilawa coat of arms, was sketched and started in Rome, where our Stanislaw was living at the time (1779-80) and fished in Paris, at David's atelier. It represents, according to Luc de Nanteuil - author of an album on David, a history portrait. This work is 'simultaneously realistic and heroic,' and David having studied the Antiquity and Masters comes with an idea of painting the nature anew- that is 'clean colors, sharp outlines and noble composition' - 'nature idealized.'
The rider is wearing an 'informal dress, looking proud, gay[joyful] and exhilarated,' displaying complete authority and prowess of an accomplished horseman. He is seating in atypical 'French' saddle of the period but very expensive example, proper for a young aristocrat. His legs are extended completely with his stirrups' leathers long while the reins of the curb bit are relaxed. Together an perfect rider - ecuyer complete.
I am curious about the horse. It is a muscular stallion, multicolored coat, his colors are of a fashion preferred by the Polish nobility at the time. Perhaps it is a horse from his own stud, perhaps a Polish horse?
Napoleon - this equestrian portrait is very different from from the Potocki. Painted in 1800-01 (one of five, this one is the Chateau de Malmaison one), after the famous Marengo campaign, it is an apotheosis of new Hannibal and Charlemagne, who while crossing the Alps amid raging storm is about to descend on the Northern Italy and conquer it for France and himself. In fact First Consul crossed the Alps on a mule, the most surefooted mountain traveler, in a calm, mountain weather, but he made a demand on David to paint him 'calm, mounted on a fiery steed" (Calme sur un cheval fougueux ).
There is a mixture of realism and theatrical fantasy, eg the uniform is the one Napoloen wore at Marengo, obtained by the painter from Napleon's valet de chambre. The rider is very different from our Potocki, completely indifferent to his rearing mount, he is a master and hero, his eyes are meant to 'blaze like bolts of lightning that pierce through the storm and subdue the ,maelstrom'.
The horse is a paint, and one of many horses Napoloen possessed and rode. we see very little of the saddle, just a saddle skirt, but most of the tack is there, the crouper and breast plate, wide cinch, small chabraque, French military bridle of the period with double reins (for curb bit and snaffle), we see no third rein or halter. The horse has long mane and tail, beautifully rendered by the master painter. Napoleon was an artillery man and never a dashing horseman like some of his soldiers, but in this painting he is master, but in an Antiquity style, very mythical and unconvincing.
The rider's position is more akin to the antiquity method employed while riding without stirrups, most famously shown by the sculptures of Parthenon or the relieves of the Alexander sarcophagus than to the typical technique employed by the riders and cavalrymen of the period, linking our heroic First Consul with the ancient heroes and their immortal fame. Hence, all 'Hollywood', propaganda with a dash of reality :)
 Luc de Nanteuil, David, New York, 1990