The Dragon Boat Festival was originally created by the ancestors of Wu-Yue in the south to worship the dragon ancestor.
Because of the legend that Qu Yuan advocated for the promotion of the virtuous, the rich, the strong, and the military, and advocated for the alliance of Qi against Qin, which was strongly opposed by the aristocrat Zilan and others, Qu Yuan was gluttonously removed from his post, driven out of the capital, and was exiled to the Yuan and Xiang basins. Later, people also take the Dragon Boat Festival as a festival to commemorate Qu Yuan; it also commemorates Wu Zixu, Cao E and Jie Zitui.
Expanded Information
Mr. Wen Yiduo, in his article "Dragon Boat Festival", argued that the Dragon Boat Festival, which involves rowing dragon boats, originated from the Wu-Yue ethnic group in the Jiangsu and Zhejiang regions before the Warring States period. At that time, the dragon was already the totem of the Wu-Yue ethnic group, and Mr. Wen Yiduo believed that it was this dragon totem that later evolved into the totem worship of the whole nation; it was in the ritual of sacrificing to the dragon that the habit of paddling a dragon boat was gradually developed.
In the ancient canon about the origin of the dragon boat records, the earliest is appeared in the Eastern Han Dynasty. According to "things primitive" in the record: "Racing things, starting in the hook trample, today's dragon boat is also." The Han Dynasty Zhao Ye "Wu Yue Spring and Autumn Annals" also believes that the origin of the dragon boat "started in Goujian, cover pity for Zixu's loyalty". So far, experts recognized by China's earliest "dragon boat racing" graphics, found in yinzhou district, ningbo city, zhejiang province, yunlong town a village.
Baidu Encyclopedia - Dragon Boat Festival