Rastignac is initially portrayed as an ambitious young man of noble, albeit poor, extraction who is at times both envious of and naive about high society.
Although he is ready to do anything to achieve his goals, he spurns the advice of Vautrin (the series' dark criminal mastermind) and instead uses his own wits and charm (especially through relationships with women, such as his cousin Madame de Beauséant) to arrive at his ends.
His eventual social success in the fictional world of the Comédie humaine is frequently contrasted with the tragic failure of another young parvenu in the series: Lucien de Rubempré (who accepts the aid of Vautrin and ends his life by his own hands).
He makes his first forays into high society (drawing on his family's resources to the full), is tempted by but rejects the machinations of Vautrin, and is confronted by cynicism and falseness in the people he meets.
At Goriot's death, Rastignac is among the few who attend his funeral, and from the heights of Père Lachaise Cemetery he looks down on the French capital and makes his famous proclamation "À nous deux, maintenant!"
1834 – Une ténébreuse affaire (1841) – Rastignac appears as one of the people to whom a denouement is made, 30 years after the narrated events occurred.
On the personal side, Rastignac's younger brother (previously unmentioned) has been made a bishop at 27, and one of his sisters is married to Martial de la Roche-Hugon, a government minister.
1839 – Le Député d'Arcis (1847, unfinished) – Rastignac is minister for the second time (of Public Works), he has been made Comte (ranking as a peer of France), his brother-in-law Roche-Hugon is now an ambassador and Councillor of State (equivalent to senator), and he is regarded as indispensable to the government.
"After 20 at hard labour" Rastignac has recently married the daughter of Delphine and Baron de Nucingen (their only child, and thus the inheritor of their vast fortune).
Rastignac's scheme fails and, despite unexpectedly remaining in power, he resorts to underhanded methods to discredit the new member for Arcis, Charles de Sallenauve (née Marie-Gaston).
1822–1824 – Le Cabinet des Antiques (1837) – Rastignac appears as one of the dandies that Victurnien d'Esgrignon falls in with during his sojourn in Paris.
1838–1846 – La Cousine Bette (1847) – Rastignac does not appear personally, but is so influential that he is among the first people considered when the Hulot family seek to have Wenceslas Steinbock's artistic talents recognised.