A bronze relief medallion by Depaulis depicting Napoleon lying dead at Saint Helena to one side and the return of his body to France on the other.
 
Napoleon Lying Dead at Saint Helena and 1840 Return to France commemorative bronze medallion by Alexis-Joseph Depaulis. This would appear to be a 1972 restrike.  The obverse features the head of Napoleon with a laurel wreath resting on a cushion.
The legend reads: SAINTE HÉLÈNE V MAI MDCCCXXI' (5/5/1821). JE DESIRE QUE MES CENDRES REPOSENT SUR LES BORDS DE LA SEINE, AU MILIEU DE CE PEUPLE FRANÇAIS QUE J'AI TANT AIMÉ (I wish my ashes to repose on the banks of the Seine among this French people, whom I have loved so much.)
The reverse features the paddle steamer Dorade which took Napoleon's remains from La Normandie near Rouen to just outside Paris in December 1840. 
The legend reads: S.A.R. LE PRINCE DE JOINVILLE COMMANDANT DE L'EXPÉDITION' (S.A.R. The Prince of Joinville commanding the expedition). PASSAGE A ROUEN DE RESTES MORTELS DE L'EMPEREUR NAPOLÉON LE X DECEMBRE MDCCCXL (The passage to Rouen of the mortal remains of the Emperor Napoleon, 10 Dec 1840).
Approximate dimensions are 6.3 cm diameter and 0.7 cm thickness. Approximate weight is 148 grams.