First there is a writing brush before calligraphy can be written with writing brush. According to legend, the writing brush was invented by Meng Tian. He was a general under Qin Shihuang. After Qin unified the six kingdoms, Meng Tian led his army to defeat the Xiongnu and regained a large area of ??land. At that time, Qin Shihuang's military discipline was strict. All major military information was reported within a time limit, and anyone who delayed would be punished with capital punishment. Meng Tian was very troubled just to report the war. Because memorials at that time were carved on bamboo slips with a knife, which was very time-consuming. In a hurry, Meng Tian took the gun tassel made of hemp and tied it to a bamboo pole. He dipped in ink and wrote a memorial on the silk. But because it was not easy to use, Meng Tian casually threw it into the lime pit after using it. Later, Meng Tian was ordered to build the northern Great Wall. Because Emperor Qin was eager to prevent dangers and kept asking about the progress of the project, Meng Tian's secretary stayed up late almost every day to make bamboo tubes to commemorate the situation. On the day of completion, Meng Tian was eager to report his merits and decided to write a memorial in person. However, it was too slow to carve the bamboo tube. He thought of what he had thrown into the lime pit last time, so he fished it out and tried it again. He found that it was much easier to use than the last time, so he was very happy. I quickly wrote a memorial on Bai Ling. Later, Meng Tian often used this kind of "pen" to write memorials, and the pen whisk was also made of wolf hair, and he named it "pen", which means made of hair and bamboo. In fact, according to literary and historical inference, the invention of the writing brush has a much longer origin, and there is also a process of gradual improvement.