He trained Jackie Chan, Sammo Hung and Yuen Biao, but who was martial arts master Yu Jim-yuen, the forgotten ‘godfather’ of Hong Kong kung fu cinema?

Despite their different looks and specialities all three were trained by the same man at the same time, at least for a few years. That man was Yu Jim-yuen. Not only did Yu train the “Three Dragons”, he also guided other important figures in the local film industry like Corey Yuen, Yuen Wah, Yuen Tai, Yuen Miu and Yuen Bun – all of whom took his name to honour him.

Given his outsize influence on Hong Kong and martial arts cinema, Yu is something of a forgotten figure. He supposedly trained his charges at Kowloon’s China Drama Academy but records are spotty about the establishment’s actual name or location. The South China Morning Post’s brief obituary for Yu refers to his school as the “Chinese Opera Research Institute” and describes it as being on the rooftop of Mirador Mansion in Tsim Sha Tsui. Another website erroneously places the school in Lai Chi Kok, probably mistaking its location for that of Lai Yuen Amusement Park where Chan and his schoolmates would sometimes perform.

Chan recollects his first visit to his future sifu in his autobiography, I Am Jackie Chan: “We pushed our way down to Nathan Road ... and then down a maze of side streets. Finally, one last turn brought us into a street lined with tenements whose windows were dark and shuttered. The sign before us proclaimed the building we were about to enter as the China Drama Academy, a name that told me nothing.” The future star goes on to describe a small courtyard and rooms beyond that – nothing like what one imagines existed on the roof of Mirador Mansion, assuming the Post’s account is accurate.

Whatever the origins of Yu’s academy, its master’s training regime has become legend for its severity. Born in Beijing in 1903, Yu moved to Hong Kong sometime in the 1950s, well-versed in the art of Peking opera and the fierce discipline traditionally required of students of the art.

To some, conditions at the China Drama Academy were “Dickensian”. Jackie Chan spent 10 years under Yu’s tutelage, eventually becoming his godson when his biological parents emigrated to Australia. Despite such a seemingly close relationship, Chan’s account of his time with Yu is far from flattering.

“Master believed in just three things: discipline, hard work and order,” Chan wrote. “Discipline came quickly and painfully, measured in strokes of the cane. Hard work was the rule of the day – a few minutes of stolen rest often meant an hour of extra practice for any unlucky students caught slacking off. And order: order was imposed by a strict line of command that placed Master at the top (never to be disobeyed or disrespected).

“The order was never to be challenged. If a brother who was more senior told you to do something, you did it. If you told a more junior brother to do something, he did it. And if Master gave a command, everybody jumped. The order was enforced by the fact that anyone who disobeyed it was beaten soundly, either by the master’s cane or, among students, by the simpler (but not any less painful!) means of a hard-swung fist.”

By all accounts Yu was a tough task master, near impossible to impress. He would pick holes in everything. If it wasn’t a student’s execution of moves that was poor, it was in the style. If it wasn’t the style, it was in the energy. If it wasn’t the energy, it was the attitude. And every mistake led to some form of physical punishment.

It was a harsh existence, even if graduates like Hung and Chan joke it about these days.