There’s a certain quality of light on autumn afternoons on the Fishbourne Marshes that speaks of childhood and the past. It tugs at the heartstrings and prompts memories of other chill October days. The sour scent of stubble burning in the farmers’ fields, the vastness of the blue Sussex sky over the Downs, the whispering of the reed beds as the tide comes in, setting the stalks rattling. A gull might wheel and cry, an oystercatcher might leave its spiky prints in the black mud by the burnt-out remains of Farhill’s Mill.

From where I am now standing, on the Bosham side of the creek, I can follow the line of the old sea wall down to Apuldram and Dell Quay, where dinghies and little boats bob in the current. I can catch a glimpse of the old flint-faced church of St Peter & St Mary in the fields framed by yew and poplar and willow trees. My sisters were married in that church, summer brides both. Ancient pilgrims’ marks are scratched into the north wall, crude yet somehow touching marks of devotion. They mean something. Beyond, on the horizon, the spire of Chichester Cathedral soars and boasts of the bustle of the town.

I was made here, this small village to the west of Chichester known, mostly, for its Roman palace. In those days, there was a general store and a post office, three public houses, – ‘The Woolpack’ and ‘The Bull’s Head’ are still going, but ‘The Black Boy’ is long since converted to housing – a primary school and a railway halt. I caught the bus or cycled if the weather was good. I played Pooh sticks with my sisters at the millpond, fed the ducks and attended the local Guides on a Monday evening. And, yes, the Marshes. In the 1960s, I explored with my parents, climbing into the branches of the stunted oak trees down by the water where a scuttled rowing boat rotted slowly. In the 70s, the teenage years, I wandered with a copy of Wuthering Heights in the hope that someone would admire such solitude. I wasn’t thinking of writing but, with hindsight, I can see that my reading was filled with novels of shifting and dominating landscape, of place. Books that belong absolutely to the place in which they are set, the time in which they are set. And although we are all guilty of rewriting the past through the prism of the present – rearranging the emotions, the facts, to suit the narrative we wish to tell about ourselves – I can see that this childhood, in that place, helped make me the writer I was to become. It’s just that I had to go away to do it.

In 1989, we bought a tiny house in the shadow of the medieval city walls of Carcassonne in southwest France. I fell utterly and head-over-heels in love with the history, with the spirit of place, with the endless Midi sky and the garrigue, the fierce Tramontana wind and the red tiled rooves of Languedoc. Sunflowers and lavender and vines. Standing on the pont vieux, which connects the medieval city on the hill to the fourteenth century Bastide on the other bank of the Aude, little by little a story – that was to become my first historical novel, Labyrinth - started to take shape. Because in Carcassonne, I had no personal history or connection. I wasn’t somebody’s daughter or sister or schoolfriend, the wonderful ties of community and family didn’t reach this far south. In Carcassonne, I was free to be a writer.

It took years before I could bring those skills home and write about Sussex – home home – rather than my adopted home. Now, after a few years of not being able to write full time, I’m embarked on a sequence of novels inspired again by French history – a new series of love letters to Carcassonne. The story of two families – one Huguenot, one Catholic – three hundred years of conflict, betrayal and intrigue set against the backdrop of the Wars of Religion. But although the series begins in Carcassonne – and will end in Franschhoek in 1862, by way of Paris, London and Amsterdam – I planned much of The Burning Chambers walking on the Marshes in Fishbourne, where memory, inspiration and imagination collide. Echoes in the landscape.

• The Burning Chambers will be published by Mantle in May 2018.