Having read both Justin Cronin’s Passage Trilogy and Chinua Achebe’s Africa Trilogy this year, I can now say I have read ten novel series!

To count as a novel series though, I think it would have to include at least three books. I don’t count a novel-plus-sequel, like Robert Graves’ I, Claudius and Claudius the God as a ‘series’. I also don’t count The Lord of the Rings for the perhaps trivial reason that it was written as one novel and only published as three separate books for other reasons.

But discounting The Lord of the Rings for that reason provokes questions. When does a series of novels become a ‘novel series’? When is a novel series really one long novel published in separate volumes?

I think there is considerably overlap between these, and there may not be any examples of either extreme, but it may be easier to distinguish the former than the latter. A lot of crime novel series, for example, can be more clearly described as a series of novels. The novels are episodic, enclosing a complete story. Even if there is a larger story transcending the individual novels and the recurring characters evolve over time, it is not often a serious inhibition for an unfamiliar reader to start with a novel picked at random from the set.

Perhaps Chinua Achebe’s African Trilogy, which I have just finished, could be considered as inhabiting one extreme. It can be argued to be three separate novels. The connections between them – in terms of things like common characters, or connections between characters – are unimportant. Instead, what they tell together is an evolution of colonialism; three periods of pre-colonial, colonial and post-colonial experience. It is a trilogy in theme and setting but not in plot or characters. The three novels were not even published in the chronological order of the stories they contain and I read them in the order of the periods they cover, not the order they were published in.

Similarly, there are examples of novel series where an author wrote a single novel with no intention of creating a series but added to the original as inspiration or other factors demanded. Thereby creating a series with recurring characters in the same universe but not necessarily with a larger plan in mind. Examples of this might be Douglas Adams’ Hitchhiker’s Guide to the Galaxy, at least at first, or the novels of PG Wodehouse.

Also, are there examples of series, science-fiction and fantasy series for example, where the main factor the novels have in common is the same fictional universe, but with no story links between the novels, no recurring characters in major roles or overarching story? I have a possible example of this in mind but I don’t know for sure and don’t want to know until I have read the series.

The other extreme may be more difficult to define. Last year I read Hilary Mantel’s Cromwell Trilogy. I think it has mostly been considered to be a novel series, not one novel in separate volumes. Yet, there is not much of a time gap between the events of each novel, if any. Also, themes which emerge part way through the first novel, Wolf Hall, continue into the second novel, Bring Up the Bodies, and themes which emerge partway through the second novel continue into the third, The Mirror and the Light. Reading them together, as I did, they do feel very close, almost a single novel, just as reading The Lord of the Rings felt.

I wonder what other series we may think of as really one novel if we reconsidered. Ford Madox Ford’s Parade’s End? Ferrante’s Neapolitan novels? Murakami’s 1Q84?

I’m not yet sure if there is a spectrum between the series of novels, the novel series and the single novel in multiple volumes but I do think occupying an extreme creates problems. For example, even a series of episodic novels would still have to include some evolution of the recurring characters as their experiences of the events of the novels change them. If including a larger story transcending the episodes would make the novels more compelling, it would be difficult to omit. Also, even a single novel published in separate volumes would have to create the illusion of new beginning and some sense of closure with each volume to make them more satisfying.

All this can be used to make a mockery of the list of novel series I have included in my completion of ten and the ones I have excluded.

Anyway, the ten novel series I have completed are:

• His Dark Materials by Phillip Pullman
• The Millennium Trilogy by Stieg Larsson
• The Cairo Trilogy by Naguib Mahfouz
• The Raj Quartet by Paul Scott
• The Chronicles of Narnia by CS Lewis
• The Ibis Trilogy by Amitav Ghosh
• The Hitchhiker’s Guide to the Galaxy by Douglas Adams
• The Cromwell Trilogy by Hilary Mantel
• The Passage Trilogy by Justin Cronin
• The African Trilogy by Chinua Achebe

I try to read a novel series every year. For the foreseeable future that may still be achievable, but some of the ones I intend to eventually read are very long and I will either have to space them out or let them dominate my reading for a year or more. I still haven’t read Harry Potter. I don’t know when, if ever, I will get to A Song of Fire and Ice. And I try to avoid thinking about reading Proust, but may find a way there in the end. Some series I will read sooner than that include:

• The Regeneration Trilogy by Pat Barker
• The Jeeves and Wooster novels by PG Wodehouse
• A Series of Unfortunate Events by Lemony Snicket
• The Maddaddam Trilogy by Margaret Atwood
• The O Trilogy by Maurice Gee
• The Alexandria Quartet by Lawrence Durrell
• The Forsyte Saga by John Galsworthy
• The Accursed Kings by Maurice Druon
• Parade’s End by Ford Madox Ford
• The Copenhagen Trilogy by Tove Ditlevsen

Not included in the list above are two series I plan on reading next year! I’m not going to spoil my 2023 Reading List! Instead, I will be posting it in December.