Erich von Däniken, the Swiss author who popularized the idea that aliens visited ancient civilizations, died on Jan. 10, 2026, in a hospital in Interlaken. He was 90. His daughter, Cornelia, told the Swiss news agency Keystone-SDA that he died of old age.

He was 32 and managing a hotel in Davos when his first book came out in 1968. Published in English as Chariots of the Gods?, it argued that ancient peoples, including the Maya and the Egyptians, got advanced technology from alien astronauts. Several publishers turned it down before one agreed, on condition that a professional writer fix the manuscript. Around then, a fraud conviction tied to his hotel job sent him to prison for 18 months. By the time he got out, the book was earning him a fortune.

More than two dozen books followed, along with documentaries and a theme park, Mystery Park, which he and a group of investors opened near Interlaken in 2003. Lifetime sales are usually put in the tens of millions. Director Roland Emmerich has said the idea for Stargate came from the 1970 documentary version of Chariots.

Archaeologists and scientists dismissed his work from the start. One anthropologist called the book a parody of reasoning built on selective quotation and error. His audience didn’t care, and his ideas live on in shows like Ancient Aliens, where he was a regular guest. He is survived by his wife of 65 years, Elisabeth, his daughter and two grandchildren.