Baroness Emmuska Orczy 
The Uncrowned King [EPUB ebook] 

It is about what happened after the death of Louis XVII, that is so amazingly interesting. Through various entries Cardinal Beneventy’s diary, we can follow the drama step by step and Emmuska Orczy has taken the liberty of forming from these fragments a coherent story—the life story not of the rescued Dauphin himself, for that was uneventful, but that of his son, known to a narrow but intensely loyal circle of royalists as Louis XIX.