Luckily, my neighbour and friend Harriet Sergeant has also recently taken up riding. Although a fearless skier and traveller (she was once shot at with a Kalashnikov while working as a journalist in Mozambique) she used to sweat with terror on a horse. But after taking her daughter for lessons at the local stables she was hooked. She bought Alfred, the riding school favourite. Such was her enthusiasm that even before Alfred’s arrival, Harriet could be found shopping in Chipping Norton dressed in jodhpurs, chaps, leather boots and a hunting jacket. Unfortunately Alfred did not live up to the outfit. Thousands of pounds and countless hours have been fruitlessly spent trying to make short-legged, dinosaur-necked Alfred look a bit more upmarket, but Harriet adores him anyway. Every weekend Harriet and I get together and ride. In reality this is not as straightforward as it may sound. Hours are spent poring over Ordnance Survey maps discussing the right route (no streams: Alfred doesn’t like water). Alfred then has to be boxed over. Harriet has to get dressed (she now looks like she’s stepped out of a Burberrys ad). The children have to be entertained, the dogs tied up and the husbands motivated.

            Once on the horses, the complications don’t end. My horse goes too fast, hers too slow. In order to communicate I am forced to yell as she trails along a mile behind. When we canter she sits back looking relaxed and happy as Alfred lollops along. I, however, hang on for dear life, perched on the back of what might as well be a Scud. Instead of cholesterol controlling my horse, there’s been a role reversal — he now controls me. After every ride I come home exhausted, my arms hanging out of their sockets and my legs shaking like jellies. Trotting behind me is a complacent Harriet. “Perhaps,” she says, irritatingly, “you should sell Tex and buy something more suitable.”

            Another friend, Sophie, wife of the writer and film director Bruce Robinson, moved from Los Angeles to a farmhouse in Herefordshire. As time passed her happening film friends were replaced by horsy neighbours. Five years on, the kitchen looks like a tack room. In order to make a piece of toast or boil the kettle you have to remove the rugs, bridles, tail bandages and numbeners draped over the Aga. Hours are spent laundering tails and painting hooves. Bruce, who is terrified of horses, wanders around looking baffled: “The French have got the best idea they serve them with potatoes and peas.” What happened to the glamorous girl in the slinky Voyage dress who used to pay him all that attention? He feels so saturated in horse talk that he refuses to call the tack by its correct names: thus, reins are known as “steering strings” and stirrups as “foot rests”.

            This summer my horse and I went to stay with Sophie. When not riding, a great deal of time was spent discussing what to do about Sophie’s new cob, Heidi, who has a mane that sticks up like a loo brush. She looks like a zebra. Having spent a fortune on Frizzese gels and hair oils, Sophie has now bought a special orange Lycra tube to stick over Heidi’s mane. So far it’s had no effect but Sophie lives in the hope that one day she will take it off and find lovely silky hair underneath. We have discovered that if your horse looks good, you look good. This explains the hours that go into grooming, the mania for plaiting and polishing, and the obsession with outfits and tack that characterises the horse world.

            So what is it that makes them so wonderful? In my husband’s opinion it is that, having subdued him, I have now moved on to my horse. I am guiltily aware that there is an element of truth in this: I am having an affair with Tex. That heady sense of being on the edge- of control with an animal much bigger than myself gives me a feeling of wild euphoria. The elation of charging through the fresh air, through the countryside I never see except in this way, the sensation of being alive, at one with an animal that I have (almost) subordinated to my will, justifies all my passion.

Twenty minutes later I was led to the stable to encounter a frightful brute, eyeballing me with undisguised malevolence from the far corner of her stable. I asked nervously if Bonny had ever kicked. “Oh no, she just makes funny faces when you put her saddle on,” the bosomy woman chirped. I soon discovered what a funny face meant, when a few moments later, the horse bared her teeth and bit the woman hard on the bottom. Horrified, I backed out of the stable, leaving Bonny with a mouthful of tweed.

            My next encounter was with Prince, a handsome black horse. Prince had been advertised as “bombproof”. A friendly-sounding man spent an hour on the phone telling me that Prince had been hunted by their six-year-old son. “He’ll do whatever you want him to do,” he assured me. “If you want to canter, he’ll canter, if you want him to walk, he’ll walk.” I asked if he’d ever bitten anyone. There was a pained silence.

            This paragon of virtue was stabled in Somerset, but I decided it was worth the three-hour drive. When I arrived the family all came out to the field where, saddled and ready, Prince was patiently waiting. One by one they got on and walked around the field. Prince looked so docile and kind I decided it was time to have a go myself. We walked and then trotted. And then he started to canter. I pulled at the reins but to no effect. The more I pulled the faster he went. I started to panic. Suddenly he put in a massive buck. I yelled and grabbed on to the mane, my legs flying in all directions. But by now he was galloping flat out, bucking and snorting as my life flashed before my eyes. I was going to be killed on a child’s pony. In desperation I steered towards the group, sending them scattering in all directions. As I lay in a pile on the ground I heard the remark that was going t 3 become all too familiar: “What could have got into Prince? He’s never done that before!” It became clear that when it comes to selling a horse there are no depths to which people will not sink. Even the most respectable middle-class mother will suddenly turn into a bare-faced liar. I was bolted with, bucked off, stamped on and humiliated. It was never the horse’s fault. My seat was no good, my hands were too heavy, or I was mysteriously “communicating my nervousness”.

            So I set my sights a little lower. With an increasingly jaundiced eye I scoured Horse And Hound, circling anything described as “100% gentleman” and putting a line through anything referred to as “forward going”. After travelling miles all over the countryside, I eventually found a palomino that cut the mustard. If I leant back and pulled with all my strength on his Dutch gag I was just able to stop him taking off into the sunset. After endless negotiations with a sobbing teenager and her aunt, I took Tex back to Oxfordshire with me. (I’ve since bought two more.)

A childhood passion resurfaces… Zara Colchester would give her kingdom for a horse

When I was five my parents divorced and my brothers and I moved from London to a cottage in the country with my mother. This marked a turning point in her life. Faded photograph albums record earlier days of open-topped Mercedes, Cap Ferrat, and holidays in St Moritz accompanied by David Niven and Elizabeth Taylor. My earliest memories are of her scent and diamonds as she leant down to kiss me good night before going out to dinner.

On moving to the country her transformation could not have been more complete. Clothes, glamour and high society no longer meant anything to her. She slobbed around in brown stretchy “pants” and ate in the kitchen with us. Photo albums were now dominated by a new and all-consuming passion: horses. Every afternoon after school, my brothers and I would be made to clamber on to our ponies (in my youngest brother’s case, a donkey) and follow my mother as she galloped madly away across Chobham Common. Inevitably one of us would be bucked off, but we got little sympathy. Although I broke my arm and my mother suffered serious concussion, the ritual daily rides continued.

There’s no doubt that my mother was in love with her horse. At lunch time Zig Zag was encouraged to come into the house and eat grapes from the dining room table. Every photograph seems to feature him. This passion rubbed off. As a child I didn’t just like ponies, I wanted to be one. For hours I’d canter around our garden, an orange wig from Woolworths aloe vera juice stuck to my bottom, making high-pitched whinnying noises and jumping little obstacles. I later realised that neither my mother nor I were alone. You don’t need to be a Badminton three-day eventer or even a nine-year-old girl at pony club to become obsessed. “I’ve always wanted a horse as a friend,” admits Aria Ashley, a 40-year-old mother of two. “I just love the way they breathe, the way they smell. They are so nervy they sleep on their feet. To have their trust is the ultimate compliment.”

On reaching their late thirties an unlikely assortment of my friends seems to have taken up riding. Like all converts they are fanatical. Bemused husbands look on as their once glamorous wives stagger in from a ride, three hours late for Sunday lunch, caked in mud and old hay. The cooking, the garden, the husband and even the children have taken second place to the horse.

For me, horse life ended when I was nine. My mother died, the horses were sold. We moved back to London and lived with my father. My friends went to nightclubs, not pony clubs. I grew up, talked about boys and diets, went shopping in Biba and listened to Cat Stevens. But then, 25 years later, staying with my mother-in-law in Oxfordshire, the bug bit again. Peering out of the kitchen window at horses clip-clopping past in the early morning mist, I announced to my surprised husband that I wanted a horse. Romantically — and naively — latching on to this new enthusiasm, he agreed to buy me one.

I set about horse-hunting. If you think a nice husband is hard to find, try finding the right horse. Out to impress, I wanted a looker. I had, of course, been warned not to trust anyone selling a horse but I couldn’t believe I had to take this advice literally. I was wrong. My first stop was East Sussex where I was welcomed by a bosomy country woman dressed in tweed. Over a cup of Gold Blend she explained that as her daughter was now “into boys” they’d all decided that Bonny, a prancing chestnut thoroughbred, would have to go. “To know Bonny is to love Bonny,” she assured me tearfully.