The term Watcher refers to angels, messengers and guardians in ancient texts. In this context, The Watchers are a group of Fallen angels that came to earth, took wives and taught mankind advanced knowledge that led to their corruption. Their children, the Nephilim, were giants and promoted great bloodshed and warfare. Because of the influence of The Watchers, mankind became so corrupt that God sent the flood to wipe the evil from the world.
The Watchers are mentioned
repeatedly in the Old Testament, Jewish Midrash, Koran, Book of Jubilees, Testaments of the Twelve Patriarchs, Damascus Document and Kabbalah. The books 1 Enoch and 2 Enoch go into great detail regarding Watchers, listing their names and specific knowledge taught to mankind. The Jewish historian Josephus talks about them in Antiquities of the Jews as does Philo’s Commentary of Genesis 6.
There is exhaustive evidence that Watchers existed and they had knowledge and power beyond our understanding.