Mary, it should be remembered, was closely allied to France by education and marriage, and the French never forgave Elizabeth the part she played in the tragedy.
The fourth volume comprises three widely dissimilar tales.

One of the strangest stories is that of Urbain Grandier, the innocent victim of a cunning and relentless religious plot.

His story was dramatised by Dumas, in 1850.

A famous German crime is that of Karl-Ludwig Sand, whose murder of Kotzebue, Councillor of the Russian Legation, caused an international upheaval which was not to subside for many years.
An especially interesting volume is number six, containing, among other material, the famous "Man in the Iron Mask." This unsolved puzzle of history was later incorporated by Dumas in one of the D'Artagnan Romances a section of the Vicomte de Bragelonne, to which it gave its name.

But in this later form, the true story of this singular man doomed to wear an iron vizor over his features during his entire lifetime could only be treated episodically.