There is nothing like a good old family Christmas

It's possible that we own the world's oldest paper Christmas decoration.

"Bally", as this large fold-out ball is imaginatively named, sleeps in the attic for 11 months of the year but today I'll bring him down and dust him off. Bally really belongs to my uncle, who will be 88 next birthday. He was given Bally for Christmas when he was two.

Bally is a fragile paper sphere, once a large honeycomb of bright colours. Year after year he hung from the dining room ceiling, presiding in ever-decreasing splendour over the festive feast.

Too weak now to be hung up, his colours faded to an almost uniform parchment, Bally is a decoration that can no longer honestly be said to decorate. But he will sit quietly on the piano, a link with those distant Twenties Christmases, a symbol of the family continuity which for me is what Christmas is all about.

I live in the house where I grew up, and I've never spent Christmas Day anywhere else. My half-century of Yuletide repetitiveness is the result of circumstance as much as choice. I took over here at Hancox, the family house, nearly 21 years ago, when I had George, my first baby. George and my second son, Sam, both turned out to be autistic.

Travelling with autistic children is difficult at any time, let alone at Christmas; inflicting autistic rigidities and eccentricities on other families is not the most thoughtful gift you can bestow. It's easier to stay put. Where will I be spending Christmas? Here at Hancox. Where else?

When George was little, he was afraid of Christmas. Wrapped presents confused him, the influx of people overwhelmed him, and the thought of a bewhiskered intruder coming down the chimney was horrifying — "No, Father Christmas is NOT coming to George's house," he would state.

After 20 goes he's got used to it, and now he loves Christmas. He has announced that he is going to sleep in the drawing room, where we have the tree and presents. There's a painting of St Jerome, a white-bearded, red-robed individual, on the drawing-room wall; George calls him "the Christmas fellow", and wants to keep an eye on him.

George is the only regular church-goer among us. We will walk with him across the frozen fields to Midnight Mass; on the day, he will sing carols, supported by his non-autistic brother Jake, while his granny accompanies them on the piano.

The lack of cynicism and materialism that is an attractive feature of the autistic condition is especially evident at Christmas. George will be as pleased with a lollipop costing 30p as with a computer game costing £30. He takes deep and immediate pleasure in simple things. He announced that winter was his favourite season. When asked what he liked about it, he replied, with a smile of intense, dreamy satisfaction: "Gloves!"

Managing Sam's Christmas involvement is more challenging. He likes to cook but his exuberant, not to say violent approach turns the kitchen into the set of an It's A Knockout Christmas Special. He loves smashing china and glass.

Last year, this got so bad that instead of dinner we had Christmas breakfast, because Sam is sluggish and docile at breakfast time. This year he's calmer, so I'm reinstating dinner, but it's unlikely he'll sit down and eat with us.

Wallace and Gromit will keep him happy while we chomp through our traditionally salt-, fat-, and sugar-saturated repast. When it comes to the pudding, Sam's festive input will reveal itself. He "helped" make it, and added a few mystery ingredients that I found it impossible wholly to extract.

I will boil the sabotaged pudding in a pan that came with the new Aga that arrived in 1934. I like doing this, just as I like re-using wrapping paper. I also like decorating the tree with Jake, and telling him the stories behind the decorations that, like Bally, live in the attic, in old cracker boxes.

Some are beautiful, like the Victorian painted birds with spun-glass tails; some are ugly, like the thick yellow and green tinsel I admired in the Seventies. There's a corn dolly made by cousin Henry, wartime efforts made by my aunts out of scraps of silver paper, pretty painted eggs from Jake's father's Hungarian relations, salt-dough shapes made by Jake himself in his primary school days.

My grandfather kept a diary every day of his adult life; I checked his wartime Christmas entries to see how much had changed. The blackout provided excitement as well as inconvenience — "The children had a wild game of ghosts in the dark house." Holly and ivy was carried to the church by pony cart, because of petrol rationing.

In 1940, he "learnt that a German bomber had come down in flames at Etchingham", a nearby village where my brother now lives, where we will enjoy a family lunch on Monday.

Wartime presents were, of course, not lavish; my grandfather's main gift was a pair of wristlets knitted by his wife, while their seven-year-old daughter got a pair of scissors. Our idea that church attendance is in decline is not borne out by the diaries; at eight o'clock service on Christmas Day, 1941, there was a congregation of only 12, with my grandfather and uncle the only men.

But the shape and structure of the day has remained the same. We sing the same carols; we fill the house with holly and ivy, not forgetting holly horns for our plaster-of-Paris imp who hangs in the hall; he lost one leg when a doodlebug shook the house in 1944.

Like any family, we fall victim to seasonal hazards — bad temper, forgetting things, overindulgence, flu. As I write, Jake's in bed with a flushed face and a nasty cough. Doing Christmas our way isn't the best or the only way; it's just the way we do it. And I know my grandparents would feel great satisfaction to see their descendants sitting round the same table under the same roof. My father always proposes the Christmas toast — "Here's to all those that we love, and here's to all them that love us, and here's to all those that love them that love those that love them that love those that love us." That just about covers it.

Hancox: A House and a Family, by Charlotte Moore is published by Viking