Wu Zetian is a unique female emperor in Chinese history. From the abolition of emperor Ruizong of Tang Dynasty in 690 A.D. to the restoration of emperor Zhongzong of Tang Dynasty in 705 A.D., she became emperor for 15 years.
If you include the actual time of manipulating the government, it is almost 50 years. But the "no word stele" erected in front of her mausoleum has always been a mystery.
Why did Wu Zetian set up a tablet without words for herself? An analysis of the real reason why Wu Zetian set up the wordless stele
There are three mainstream views about the "wordless stele" she set up for herself: Wu Zetian built the tablet to boast her merits and virtues, and "wordless" meant to show her achievements, and the words were hard to write. The other is that she knows that her sin is too great to write about. There is also a popular saying that Wu Zetian set up the tablet without words to let future generations comment on their merits and demerits.