521 BC e.

• 521 - Beginning of classes at the Croton School of Pythagoras.
• 521 (519) - Oroit, governor of Lydia, Phrygia, and Ionia, was killed by Darius for refusing help.

China

• The 21st year of the reign of the lutsk prince Zhao-gong ^[1] .
• Tsai Ping-gun was buried in the 3rd moon ^[2] .
• In the summer, the Jin ambassador Shi Yang ^[3] arrived in Lu , who was not sufficiently respectfully met (equating the tsisk to rank ), but in response to his remark, they brought the necessary things to a higher rank ^[4] .
• The allies from Wu came to the aid of the Hun clan of Hua, and the Qi army came to the aid of the Song . In the summer from Chen, detachments of Hua Hai, Xiang Ning, and Hua Dina invaded Song and rebelled in Nan-li ^[5] . At first, the Sungs and cists won, then Hua defeated, and the Sung gong wanted to escape from the capital, but the townspeople supported him, and when the allies approached, the gong won. Hua Hai and other rebels fled to Chu in 520, and new dignitaries were appointed to Song ^[6] .
• In the 7th moon, on the day of Ren-wu , on the new moon there was a solar eclipse ^[7] (noted in Shi Ji ^[8] ). According to modern data, it happened on June 10, 521 BC. e.
• In the 8th moon, on the e -ha day, the dignitary dignitary Shu Che died ^[9] .
• In winter, the Tsai Tao-hou (Zhu) fled to Chu , fleeing trouble ^[10] .
• In winter, the Lusk gong went to Jin , reached the Yellow River, but Jin was refused admission, and he returned ^[11] .
• Wuhe bell was cast in Zhou . The musician Zhou-jeu said that he does not sound harmonious, because the people suffer (episode 30 " Guo yui ") ^[12] .