Immanuel Velikovsky was a Russian-born psychiatrist and author, best known for his controversial theories about ancient history and astronomy. He gained fame in the 1950s with his book, *Worlds in Collision*, where he proposed that catastrophic events in the solar system, including near-collisions of planets like Venus and Earth, shaped human history and mythology. Velikovsky's ideas challenged established scientific views, leading to significant debate among historians and scientists. His work has been associated with the fields of pseudoscience and alternative history, as many of his claims lack empirical support and are not widely accepted in the academic community.