Taijitu seen in Tripilja culture in Ukraine, displayed in the Ukraine pavilion at the Expo 2010 in Shanghai, China. Also, the interlocking design is found in artifacts of the European Iron Age. While this design appears to become a standard ornamental motif in Iron-Age Celtic culture by the 3rd century BC, found on a wide variety of artifacts, it is not clear what symbolic value was attached to it. Unlike the Chinese symbol, the Celtic yin-yang lack the element of mutual penetration, and the two halves are not always portrayed in different colors. Comparable designs are also found in Etruscan art.
Zhou Dunyi credited in Taoism as the first philosopher to popularize the concept of the taijitu or "yin-yang symbol". Born in 1017 in Yingdao County, Daozhou prefecture, in present-day Yongzhou, southern Hunan, Zhou was originally named Zhou Dunshi. Raised by a scholar-official family, he was changed his name in 1063 to avoid a character in the personal name of the new Emperor Yingzong. His father died when he was fourteen and he was taken in by his uncle Zheng Xiang. He received his first posting in government through his uncle. Although very active in his civil service career, he never did achieve