Thanks to internet, you can find tutorials about pretty much anything. In earlier times such records of everything were not available. You had to build skills on your own, or with the help of people around you who had learned them before. Craftsmen’s skills were often transmitted within the family and often over several generations. That’s how families could become specialised in, say, baking, carpentry, or forging. Such a set of skills, when acquired and mastered through many years of hard labour, is called gongfu in Chinese, a term best known with the alternative spelling kungfu which is in fact not originally specific to martial arts.
The set of skills displayed in the Chen family entails a similar craftsmanship. The population in rural villages had to defend against banditry while still being able to work on the fields. A discipline had to be devised in order to teach some self defense while training the body in a sustainable way. Taijiquan, along with other Chinese martial arts, slowly emerged by combining many things together: a Chinese Daoist alchemy fostering body-spirit cultivation, a centuries-old tradition in medicine, meditative practice and gymnastic exercise, as well as ancient warfare concepts and strategies. These different teachings constitute a system that has been built up, passed down, cared for and improved upon over many generations and has reached a very sophisticated level.
Chen Yu represents the current 19th generation in the Chen family; his taijiquan skills, first learnt from his father Chen Zhaokui, are powerful. He teaches in China. Nabil Ranné is his direct disciple and the co-founder of the Chen Taiji Network Deutschland (CTND); I have been learning from him and the CTND "family" for the most part of a decade.
If you want to learn more about our training, head over here.