Huaiyi (懷義; died December 25, 694), né Feng Xiaobao (馮小寶), also referred to as Xue Huaiyi (薛懷義), was a Buddhist monk who was known for being the lover of Wu Zetian, the only female emperor in the history of China. Huaiyi, whose birth name was Feng Xiaobao, was from Hu County (鄠縣, in modern Xi'an, Shaanxi). He was making a living by selling medicines on the streets of Tang Dynasty's eastern capital Luoyang, when he was spotted by Princess Qianjin, a daughter of Tang's founder Emperor Gaozu. In or before 685, she recommended him to Empress Dowager Wu, later known as Wu Zetian, then regent over her son Emperor Ruizong. Empress Dowager Wu favored him greatly, and in order to facilitate his being able to come in and out of the palace, had him undertake tonsure to become a Buddhist monk with the name Huaiyi. Because Huaiyi came from a lowly household, in order to elevate his status, Empress Dowager Wu had him adopted into the clan of her son-in-law Xue Shao (薛紹) (the husband of her daughter Princess Taiping) and had Xue Shao treat Huaiyi as an uncle. It was said that when Huaiyi entered and exited the palace, he would ride on an imperial steed and have some 10 eunuchs attend to him. Whenever people saw him, they avoided him—because he was accustomed to batter those who came near him and toss them aside. He was particularly hateful of Taoist monks, and whenever he encountered them, he would batter them severely, sometimes cutting their hair off. Even the most honored governmental officials, including Empress Dowager Wu's powerful nephews Wu Chengsi and Wu Sansi prostrated themselves before him. He gathered a group of young thugs and had them undertake tonsure but serve as his followers. When these followers carried out unlawful deeds, few officials dared to speak about this. One exception was the assistant censor Feng Sixu (馮思勗), who punished them according to their deeds, and on one occasion, when Huaiyi encountered Feng Sixu on the road, he had Feng Sixu battered so severely that Feng Sixu nearly died.