The number 666 is thought to be the Number of the Beast, so people once thought that the year 666 was to be the year of the advent of the Antichrist. 666 - The Number of the BeastThe fear of the number 666 is known as hexakosioihexekontahexaphobia.
Events
Chertsey Abbey is founded.
Barking Abbey is founded.
Wilfrid returns from France freshly consecrated as Bishop of York.
Muawiyah I accedes to the position of Caliph.
Again, the Chinese Buddhist monks Zhi Yu and Zhi You craft more South Pointing Chariot vehicles for Emperor Tenji of Japan, as recorded in the Nihon Shoki (the South Pointing Chariot is a non-magnetic, mechanical-driven directional-compass vehicle that incorporates the use of a differential gear).
Deaths
November 26 ? Yeon Gaesomun, dictator of Goguryeo (birthdate unknown; other sources indicate death date as 664 or 665)
Dou Dexuan
Li Yifu
Liu Xiangdao