Who was the pre-astronautics specialist Zecharia Sitchin ?

Zecharia Sitchin (born July 11, 1920 in Baku, † 9 October 2010 in New York) was an American bestselling author.
Sitchin was a prominent representative of the pre-astronautics. In his books, he set about the translation of ancient pre-Christian Sumerian cuneiform texts, the theory that colonized that in prehistoric times, aliens who Anunaki coming from Nibiru, a hypothetical twelfth planet, the earth and man were created as slaves. The man had to perform on behalf of aliens, especially working in mines. The aliens have visited for 432 000 years the earth before environmental problems on their home planet, where the pyramids in Egypt had served as landing aids. The aliens were mixed with human women and more. 13,000 years ago, finally, a great flood would have killed countless people, whereupon it came to war between the humans and the aliens.