In A Tale of Two Cities, the title "Marquis St. Evrémonde" is held by Darnay's uncle, but had previously been held by Darnay's father, for according to Dr. Manette (book III, chapter X) Darnay's mother had been "the wife of the Marquis":
“The lady was young, engaging, and handsome, but not marked for long life. She was in great agitation. She presented herself to me as the wife of the Marquis St. Evrémonde. [...] When I handed her down to the door, there was a child, a pretty boy from two to three years old, in her carriage. [...] She kissed the boy, and said, caressing him, ‘It is for thine own dear sake. Thou wilt be faithful, little Charles?’
How does the inheritance of the title work? If basic firstborn male inheritance was in play, Darnay would be the Marquis at the time of the main story, but the title seems to have gone laterally within his father's generation rather than being passed down to him.
(Alternatively, I would be happy with an answer that pointed at some critical commentary treating Darnay’s mother’s reference to her being the wife of the Marquis as an error that should have been something like “wife of the Marquis’ brother”.)