Under a billowing mulberry tree on the grounds of the Royal University of Phnom Penh, around 30 martial artists undergo their daily training under the instruction of a master.

They each stand on one leg while punching and elbowing the air for exactly 42 seconds, and then repeat the exercise with the other leg as support. Meanwhile, the master walks around kicking each student’s weight-bearing leg. If their stances are not firm enough, they will fall. For Narak Neakak, a master of the ancient Khmer martial art Yuthakun Khorm, the session is not simply an exercise – it’s an essential part of survival.

“Yuthakun Khorm is not something you take for granted,” Neakak says. “It could be a matter of life and death.”

While the origins of the martial art are disputed, one thing is clear: the seldom-discussed form is meant for real fighting.

According to You Sinet, the founder and chairman of the Yuthakun Khorm Federation, the martial art is one of the three components that made up Moha Yuthakun Khorm, or the Art of War. The other two involved magic spells and military strategy.

“In the past, our ancestors created one of the biggest empires in Asia,” Sinet says. “They must have had a great art of war in order to expand and defend the country. Our research found that Yuthakun Khorm was created and applied by King Jayavarman VII.”

While Kun Khmer, a form of kickboxing whose competitions are broadcast almost every day on local TV channels, and l’Bokator, another ancient form of self-defence, have growing visibility, Yuthakun Khorm is less well known despite its long history in Cambodia.

Nonetheless, in recent years the sport has received a bit of a boost, with classes being introduced two years ago into the curriculum at universities, according to the federation, which is responsible for coaching and preserving it. It is also being taught to certain units in the military. Currently, approximately 2,000 people are learning the martial art nationwide.

Despite the rough training – including 360-degree jumps and sparring involving punching, kneeing, elbowing and kicking – most of Neakak’s students are accustomed to the pain.

“On the first few days of my training, I ached all over my body, and was sick as well, because I used to be very fragile,” says Seng Dara, a 27-year-old Phnom Penh native. “But after two years, this is nothing to me, and I feel stronger and healthier.”

Seak Sethkathiya, a 26-year-old student from Kratie, says Yuthakun Khorm helps her feel safe living in the city.

“I left my hometown for Phnom Penh to study and work,” she says. “My family is very worried about me, so I have to learn to defend myself.”

One of the surviving masters, Chan Bunthoeun, 62, who first learned the fighting style from his father, explained that the form was meant for the battlefield because it incorporates all forms of fighting techniques, including combat with both bare hands and weapons, such as swords and spears, as well as grappling. It also involves dark magic used to defeat opponents.

“In addition to the strength of an elephant and the speed of a leopard, a Yuthakun Khorm warrior uses magic spells to help them knock down their opponents,” he says.

“For example, Moha Kamlang is a spell that makes you powerful during the fight,” he added, referring to a spell that is said to give fighters a sense of strength.

A former commando in the 1960s and 1970s, Bunthoeun says the knowledge of Yuthakun Khorm saved his life throughout countless combat missions. He also claims to know the spells that make him invisible and prevent him from being hit by enemies.

His son, Chan Rathana, a Kun Khmer fighter and Cambodian star on the Singapore-based mixed martial arts circuit ONE Championship, says Yuthakun Khorm is behind his ferocity in the octagon cage.

“Many Cambodian Kun Khmer practitioners got into MMA but could not find success because Kun Khmer is mainly based on striking while standing,” he says. “On the other hand, Yuthakun Khorm, with its ground and grappling techniques, allows me to compete so well in ONE FC.”

While its practitioners point to the martial art’s Angkorian roots, Yuthakun Khorm loyalists have often disagreed with their l’Bokator-touting counterparts over which style is the oldest.

San Kimsean, a grandmaster in l’Bokator and the founder of the Cambodia Bokator Federation and the Cambodia Bokator Academy, says Yuthakun Khorm is not even a real ancient martial art, but instead is an umbrella term for all martial arts. As Khorm is derived from the word Khemara, or Khmer, and Yuthakun is a combination of the words “war” and “martial art”, he contends the term just refers to the collection of fighting styles in general.

“It is possible that the original masters who created what people call Yuthakun Khorm today knew many Cambodian martial arts, and combined them to create a style of their own,” he says.

The bas-reliefs of ancient temples in Cambodian, such as Bayon temple and Banteay Chhmar feature Khmer people using martial arts in war but there is no evidence as to whether it is l’Bokator or Yuthakun Khorm.

Meanwhile, Sinet, the federation chairman, claims that l’Bokator is just a fighting technique incorporating a staff, and points to the dictionary of Choun Nath, a former Supreme Patriarch of Cambodia and a pioneer of the modern Khmer language.

“In his dictionary, Samdech Choun Nath describes l’Bokator as only the short staff that protects the arms or the fighting technique with that,” he says. “Yuthakun Khorm focuses on many more techniques and thus should have been the first to be created.”

San Kimsean, though, dismisses the argument, saying that l’Bokator is a much broader and distinctive style than that described by Nath. Furthermore, as a monk, he challenged his expertise on martial arts.

“I first came to the world of martial arts when I was 13, and I am still in it, although I am 72 years old now,” Kimsean says. “I could not stand seeing our young generations learning a relatively new martial art and call it an inheritance left by our admirable ancestors.”