Yiquan, also known as Dachengquan or "Mind Boxing," was founded by Wang Xiangzhai. After studying Xingyiquan with Guo Yunshen, Wang traveled across China in the mid-1920s, meeting various Kung Fu masters. He concluded that the emphasis on complex movements in Xingyiquan overshadowed the development of the mind, crucial for enhancing martial skills. Thus, he created Yiquan, focusing on the mind's role in martial arts. By the 1930s, his school in Shanghai gained fame, attracting core students like Han Xingqiao and Han Xingyuan. Wang's teachings evolved, emphasizing Zhan Zhuang, a standing practice foundational to Yiquan. In Beijing, he further refined his methods, focusing on the Bao posture and simplifying practices. Yiquan, distinct from other martial arts, lacks fixed fighting techniques, instead developing natural movement and abilities through various training methods. It's characterized by the absence of traditional concepts like Qi, meridians, and dantian, emphasizing present awareness and the avoidance of preconceptions. Yiquan represents a synthesis of internal aspects from various arts Wang encountered, including Fujian White Crane, Tai Chi, Baguazhang, and Liuhebafa, emphasizing the internal core for effectiveness.

Yao Zongxun, a formal successor of Wang Xiangzhai, furthered Yiquan's development. His sons, Yao Chengguang and Yao Chengrong, continue to develop and promote Yiquan globally, known as the "Twin Stars of Yiquan" for their efforts in popularizing the art worldwide​​​​​​.

The history article will be expanded upon in the future.  Stay tuned for updates.

In the meantime, you can read the article on Wikipedia. It is very incomplete but reflects the main milestones of the original history.