Although Wu Huifei was only a concubine   of Tang Xuanzong (AD 685-762), the sixth emperor of the Tang Dynasty, her influence was far greater than most in her position.  Historians say that the ruler loved her so much that, in AD 724, he  _ his wife and made Wu a royal concubine. "Although she was only a concubine, she was treated as an empress with palace etiquette  ," explained Shi Xiaoqun, director of relics collection for Shaanxi History Museum. "Tang Xuanzong even wanted to make her his empress but was opposed by the ministers."  The emperor had thousands of concubines in his palace in Chang'an (now called Xi'an, capital of Shaanxi province) but, according to Shi, he only loved Wu, the mother of seven of his children.  Wu died in the December of AD 737 at the age of 38 and was buried in Jingling Mausoleum. She was given the title Empress Zhenshun after her death.  "It's rare for a concubine to be given so much posthumous   honor in the history of Chinese feudal   society," said Liu Daiyun, research director at the Shaanxi Archaeological Research Institute.  Her tomb ---53 meters wide by 56 meters long --- is located in the west of Pangliu village, which is part of Xi'an's Chang'an district.  The recovered sarcophagus   is 4 meters long, 2 meters wide and 2 meters tall and is decorated with flowers and maiden figures, which archaeologists say is a rare cultural relic of high scientific, historical and artistic value. In ancient times, a sarcophagus was used to house wood coffins in order to preserve the body of the noble person. "I knew it was precious but I didn't know it was so beautiful," said Han Qinglong, who headed the team that brought the relic back to China four years after it was stolen and sold abroad by tomb raiders  . The passage mainly focuses on   _  .
the life story of Wu Huifei. the reason why Wu Huifei was favoured by Tang Xuanzong the scientific, historical and artistic value of the recovered sarcophagus of Wu Huifei. the influence of Wu Huifei and her posthumous honor.