The author combined real events from his own memory with fictional scenes and tells the story from his Agenda de Liaison.
However, the central characters, even if someone thinks they recognize themselves, are almost exclusively the product of the author's imagination, with the exception of historical figures.
Anyone who thinks they can find more between the lines than in the text is welcome to join The dead poets' club. Anyone who suspects that the places named and scenes described belong to other periods should congratulate themselves. Those who nevertheless persevere to the end must be considered consistent.
Have fun!