vivasantiago:

The answer most people look for when presented with this question is “Marengo,” but the idea that Marengo was his favorite and/or his only mount is a gross misconception.  To clarify, below is a list of all of Napo’s horses, alternate spellings separated by commas and their nicknames in parentheses.

• Aboukir
• Ali, Aly, Ally (Marengo)
• Arabella
• Artaxerces
• Babylonien
• Bacha
• Belle
• Bijou
• Bonaparte, Buonaparte (Numid, Numide)
• Bouffon
• Breant
• Calvados
• Cerbere
• Chiek, Chiekh
• Cid
• Coceyre
• Conquerant
• Coquet
• Cordoue (Cuchillero)
• Courtois
• Curde
• Cirus, Cyrus (Wagram)
• Desire
• Desiree
• Distingue
• Embelli
• Emir
• Epicurien
• Estime
• Euphrates
• Extreme
• Familier
• Favori
• Folatre
• Friedland
• Gessner
• Gisors
• Gonsalvo, Gonsalve
• Hahim
• Harbet
• Helavert
• Heliopolis
• Hericle
• Hippogriffe
• Ingenu (Wagram)
• Intendant (Coco)
• Jaffa
• Kurde
• Labrade, Labrador
• Leonore
• Lowska
• Lutzelberg
• Lydienne
• Lyre
• Major
• Marie (Zina)
• Mon Cousin (Wagram, Austerlitz)
• Montevideo
• Moscou (Tcherkes)
• Naiade
• Nankin
• Naturalist
• Naufrage
• Nausicaa
• Navigateur
• Navire
• Neron
• Nickel
• Ninon
• Roitelet I
• Roitelet II
• Russe
  
• Sagonte
• Sahara
• Sara
• Selim
• Styrie
• Sultan
• Tamerlan I
  
• Tamerlan II
  
• Tauris, Taurus
• Timide
• Triomphant
• Vizir, Vizier
• Wurzbourg

Not only did Napoleon have a habit of naming horses after successful battles, but he also favoured Arabian greys, which makes identification of any single horse’s presence at a battle difficult.