Thinking about all the “family” favourites which inevitably accompany this season, I was struck by how few families featured in my childhood classics. The Pevensie children are evacuated, away from their parents, to Professor Kirke’s in The Lion, the Witch and the Wardrobe. Neither the aloof banker Mr Banks nor his slightly drippy wife (she only becomes a suffragette in the Disney film) have any adventures with Jane, Michael, John, Barbara and Annabel and their nanny, Mary Poppins. While Wendy, John Napoleon and Michael Nicholas all go to Neverland in Peter Pan, their parents do not – and it’s heavily implied in the eerie final chapter when Peter visits Wendy as a new mother, with the moonlight glinting off his milk-teeth, that parents can’t go to Neverland. Huckleberry Finn, Harry Potter, Frodo Baggins, Anne of Green Gables and Heidi are all orphans.

There are good reasons why so few children’s books feature adults. Part of their charm is in children finding their own way, their own moral compass, without an intervening grown-up. The threats are threats because there is no bigger person to pick you up.

All of this makes Tove Jansson’s adorable Moomin family a joyous anomaly. There is a nuclear family at the centre – the boyish Moominpappa, the serene Moominmamma (who, wonder of wonders, encourages children to smoke) and Moomintroll, gullible and guileless, intending to do good and invariably getting into trouble. The first book translated into English was the third book in the series: in Swedish it was called The Magician’s Hat but became Finn Family Moomintroll in English, putting the family unit at the centre of the book.

Yet it’s the fringes of these Finnish hippopotami-things that is intriguing. Moomintroll’s on-off girlfriend, the Snork Maiden, seems to live in the house with them at some point. Is she and her brother the Snork even the same species as the Moomins? (They change colour to express emotion, something the Moomins never do). Why do they have that lucre-loving weaselish creature, Sniff, as a semi-permanent houseguest? Is he a pet? And is the Dweller Under The Sink a pet or just opportunistic vermin?

While we’re on the natural history of Moomins, are the Hemulens some kind of cousin or variation? Moominpappa was raised by a Hemulen in the orphanage (elegy does seep in, regardless), and another was the very first character I identified with in literature, a Hemulen plunged into melancholy when he succeeds in finishing his stamp collection (life has become pointless: the very philosophy adopted by the Muskrat, who reads Spengler’s Decline of the West). The fact they also may have their Ancestor, some kind of ur-Moomin, living in a tiled stove in the bathing house, makes the evolutionary study of Moomins even more complex.

But it’s the non-nuclear aspects of the assorted creatures which are most striking, as they are presented as not really even worthy of comment. The vagabond Snufkin, who seems young in the books but whose name connotes old codger or scruffy old man, is the half-brother of the demonically determined Little My, who is eventually formally adopted by the Moomins. Her mother, the Mymble, had an affair with the Joxter. Although there is a tight – if xenogamous – family unit doesn’t mean this is the best or only kind of family. This is reinforced in the final book, Moominvalley In November, the only one of the novels not to feature the family. Set at the same time as Moominpappa At Sea (in which he relocated the family to a lighthouse in an exploration of loneliness), the final novel features the “supporting cast” moving into the Moominhouse and trying to become a family like the absent Moomins. Toft, the orphan, desperately wants a mother-figure; the Fillyjonk, a bossy obsessive-compulsive, wants to become more like Moominmamma in order that people will like her; the Hemulen asks for Toft’s help to build a treehouse for Moominpappa (a weird reversal of parent-child dynamics).

There’s even a Grandfather figure, trying to find the reputed Ancestor. It is interesting that although each of the characters does succeed in changing – the inspiration to be like the family works to a degree - Toft’s key understanding is that the Moomins of his imagination are too good to be true, that their perfection as a family was a fiction all along. That the book was written after the death of Jansson’s mother – she referred to it as being about how to be a mature orphan – no doubt plays into this. Her most eloquent exploration of being a family comes in a novel about attempting to be a family.

That said, my favourite of the books remains Moominland Midwinter, in which Moomintroll wakes early from his hibernation, and featuring the terrifying Lady of the Cold. Like so many of the best children’s books, it is the one where the child is thrown into a world without parents.