Taijiquan (often written as ‘Tai Chi’) comes from an ancient tradition of martial arts in China. At Rou He Daoguan, Jim Carlson teaches the Yang Family Hidden Tradition (Yangjia Michuan) Taijiquan.
Yang Luchan (1799-1872), known as “Yang the Invincible”, learned his form of Taijiquan in the early 1800s. He was a teacher who taught a modified form to the public, but taught his personal form to his family. This form was then taught to a very few family members and their students over the years. Yang’s son Yang Jianhou (1839–1917) was the teacher of Zhang Qinlin (1888–1967), who taught Wang Yen-nien this hidden tradition.
Wang Yen-nien (born in 1914) studied the Yang Family Hidden Tradition as a student of Zhang Qinlin beginning in 1945. Wang Yen-nien taught in Taiwan and at workshops around the world until his death in 2008. To perpetuate the style, he taught it to a great many students all over the world, and encouraged them to pass it along openly to their students. Wang Yen-nien also published books on Yangjia Michuan Taijiquan (available at http://www.ymti.org/us/int/Books.html.)
The European association, AMICALE, has a lot of information and other links on its website, https://www.amicale-yangjia-michuan-tjq.org/
The Great River Taoist Center of Chinese sword authority Scott Rodell in Washington, DC, has a website featuring videos and many articles, https://www.grtc.org/. Scott Rodell has also written several books on taijiquan including “Chinese Swordsmanship: The Yang Family Taiji Jian Tradition” and “Taiji Notebook for Martial Arts”.