U.S. Congressman, populist writer and amateur scientist, known primarily now for his theories concerning Atlantis, Catastrophism (especially the idea of an ancient impact event affecting ancient civilizations), and Shakespearean authorship, all of which modern historians consider to be pseudoscience and pseudohistory. Donnelly's work had important influence on the writings of late 19th and early 20th century figures such as Helena Blavatsky, Rudolf Steiner, and James Churchward and has more recently influenced writer Graham Hancock.

Table of Contents
Atlantis : the antediluvian world
Caesar's Column
Ragnarok: The Age of Fire and Gravel

Atlantis: The Antediluvian World (1882), in which he attempted to establish that all known ancient civilizations were descended from its high-Neolithic culture. 

Ragnarok, the Age of Fire and Gravel (1883), in which he proposed that a comet hit the earth in prehistoric times and destroyed a high civilization.

Caesar's Column (1890), a science fiction novel set during 1988 about a worker revolt against a global oligarchy.