The documented lineage runs to Chenjiagou, Henan, and Chen Wangting in the 17th century, a retired military man who blended boxing with breathing and channel theory. Yang Luchan learned there in the 1820s and carried it to Beijing; the Yang, Wu, and Sun styles descend from that transmission. The name taijiquan appears in writing only in the 19th century.
The counter-legend: Zhang Sanfeng, a semi-immortal Taoist, invented the art on Wudang Mountain after watching a crane fight a snake. Beautiful, unfalsifiable, and nowhere attested before the 19th century, several hundred years after Zhang supposedly lived.
The claim embedded in the form's logic: weight shifts rehearse yin-yang alternation; circles rehearse return; softness rehearsing yielding as strategy. Practitioners are enacting the Xici Zhuan's generation sequence backward, from the ten thousand things toward the ridgepole. Exercise as un-differentiation.
When did rehearsing the cosmos stop meaning rehearsing the fight?