Hampshire's Lara Prior-Palmer hands over the reins for Mongol Derby

The wild horse underneath her was likely to stir at the slightest provocation and if Lara fell now and failed to grab hold of its mane, she’d be alone in the Mongolian wilderness and forced to run a marathon before she even met another person.

All she could do was ignore the pain from 14 hours of riding and hide the aggressive sound of galloping horse hooves by softly singing the first song that came to mind over and over again to calm the horse she named The Lion.

It may not sound like the average scenario for a Hampshire teenager to find herself in, but for Lara these are the unforgettable moments that led to her winning the world’s toughest and longest horse race – the 1,000km Mongol Derby.

“I remember someone commented ‘finishing this race is like climbing Everest without oxygen’, and they aren’t far wrong.

“In my eyes it is the hardest thing you can do on a horse. It’s in its own category,” says Lara.

The 19-year-old is the current holder of three records, the first Brit, first woman and youngest person to win the race since it began in 2009, and she has now handed over the reins to this year's winner Australia's Sam Jones.

But despite her victory last year, Lara, from the historic village of Appleshaw, says at one stage she had no expectations of even making it to the end of the race.

She signed up to the event just five weeks before it began after deciding she wanted to embark on an extreme challenge to fundraise for Macmillan Cancer Support and Greenhouse Charity. Lara visited her aunt, equestrian legend and six times Badminton champion Lucinda Green.

Lara Prior-Palmer. Picture by Richard Dunwoody richarddunwoodyphotography.com

“She didn’t really know what I was getting into. She seemed quite concerned about my bottom, lent me a helmet, donated to my charities and said ‘goodbye!’ “To be honest I thought at the time I probably won’t be able to finish.

“When she picked me up from the airport when I got back, she was ecstatic. She was so excited I had won.”

But it certainly wasn’t easy.

In 1224 Genghis Khan set up the world’s first long-distance postal system using a massive network of horse stations which was used in some form until the 1960s. It saw riders travel on horseback between outposts stopping to either rest, swap horses or pass the message on to another rider.

Extreme challenge company The Adventurists, whose website states ‘this is no guided tour, or pony trek’ spoke to old riders in order to recreate the system for ten days in August, building 25 horse stations at 40km intervals along the entire 1,000km route.

The competitors choose their semi-wild horse from the local herders at each station, which are then checked by vets, and stay with Mongolian families along the way.

But there is no course set out for the 30 competitors, who have to navigate the landscape themselves.

Each day involved nearly 14 hours of riding in extreme conditions and almost half the competitors dropped out with injuries including broken ribs, crushed wrists and food poisoning.

“We all knew it was going to be painful and we were all really scared but I don’t think anyone realised just how hard it would be,” says Lara who decided to complete the entire race standing up in her stirrups.

“It lasted so long and you’re in a lot of pain. It’s not just one horse you’re riding to the extreme, it’s 25 so it’s an ongoing battle of getting the right horse.

“Some are so lazy and it’s really disheartening, some are amazing and they gallop so far and fast that you can’t believe they are horses, they’re more like lions.”

Picture by Richard Dunwoody richarddunwoodyphotography.com

Lara, who was 12 when she began riding, said it was difficult to choose a horse from the herd so her tactic was simply asking the herders for their best.

But persuading the nomadic tribesmen to give her their most dangerous was a challenge.

“In Mongolia, the women don’t ride much, so they want to give you quite a lazy, safe horse but you have to say, ‘I don’t care how naughty it is when I get on.’ “Some of their good horses are so naughty they buck you off before you can get going.

“I wanted the ones that bucked the most because once that was over, you were so thankful for their energy later.

“The wilder the horse, the better because they were so fit, they were able to be wild.”

Lara says her favourite horse was given to her on the morning of the fifth day – and she explains why she went against Mongolian culture to name it.

“He was so fit and so wild, it was like riding a lion, so that was his name.

“All the herders had to get on it before I did. When I got on it they had to hold it close to them and ride out with me for ten minutes because it was so wild.”

But despite the exhilarating ride the terrain was often inhospitable with wolves, flash floods and extreme temperatures.

Lara fell off twice after her horses tripped in marmot holes.

“I was lucky I didn’t break a bone. Both times I was lucky I held onto the ponies because as I was tumbling. I managed to keep a rein in a hand and they dragged me along.

“If you let your pony go, you are in the middle of the Mongolian steppes alone and there’s literally nothing and no one to help you and you’d have to run a marathon to the next station, so you really don’t want to lose your pony.

“I hated it physically and it was sometimes mentally draining to feel your pony struggling so much underneath you. I just thought ‘why give up? It’s just physical pain, it won’t last, you just want to get to the next station.”

That determination paid off – although her joy came at the expense of another rider.

American Devan Horn was actually the first rider to finish the race.

But race rules stipulate that each rider’s horse must pass a veterinary inspection at the end of each leg, and Miss Horn’s horse’s heart-rate did not recover in the required time. She was issued with a two-hour penalty, which handed victory to her British rival.

“It was very dramatic but with the Mongol Derby, anything can happen.

“For this year’s competitors it’s important they aren’t afraid of riding alone and a lot of it is mental strength – you have to find it all funny and ridiculous. I cried once but I was giggling minutes after”

Lara is off to Iraqi Kurdistan to ride horses to the Iranian border.

“After the Mongol Derby I see an adventure in everything. I’ve got no sense of danger anymore,” she says.

l Lara Prior-Palmer is available for motivational talks. To contact her follow @LaraPriorPalmer on Twitter.