Hari Seldon is the intellectual hero of Isaac Asimov's Foundation Series. In his capacity as mathematics professor at Streeling University on Trantor, he developed psychohistory, allowing him to predict the future in probabilistic terms. His ability to predict disasters is the reason behind his nickname "Raven" Seldon.
In the first five books of the Foundation Series, Hari Seldon made only one in-the-flesh appearance, in the first chapter of the first book (Foundation), although he did appear other times in pre-recorded messages in order to reveal a Seldon Crisis. After writing five books in chronological order, Asimov went back with two books to better describe the initial process. The two prequels—Prelude to Foundation and Forward the Foundation— describe his life in considerable detail. He is also the central character of the Second Foundation Trilogy written after Asimov's death (Foundation's Fear by Gregory Benford, Foundation and Chaos by Greg Bear, and Foundation's Triumph by David Brin), which are set between Asimov's two prequels.
Seldon was born in the 11,988th year of the Galactic Era (GE) (-79FE) and died 12,069 (1FE). In Asimov's saga, the Galactic Era had started when the Galactic Empire was founded (in an unknown date in the future, supposedly around twenty thousand years from now): the timeline can be induced from some hints Asimov dropped in his whole series, including the Robot series and the Empire trilogy. He was born on the planet Helicon in the Arcturus sector. His father was a tobacco grower in a hydroponics plant. He showed precocious mathematical abilities at a very early age. At the same time, he learned martial arts that later helped him on Trantor, the principal art being Heliconan Twisting (a form seemingly equal parts Jiu Jitsu and Krav Maga); it seems that Helicon is " much less notable for its mathematics, and more for its martial arts." (Prelude to Foundation) His biography was written by Gaal Dornick.
Using psychohistory, Seldon found the right time and place to set up a new society, one that would replace the collapsing Galactic Empire by sheer force of social pressure, over a thousand-year time span. He predicted that the Galactic Empire would fall to barbarism for 30,000 years. So, he set up the Foundation to reduce it to 1,000. The Foundation survived the first crisis and the book ends with them close passing it.
Prelude to Foundation
As a thirty-two year old assistant professor of mathematics at Helicon University, Seldon visits Trantor from his native Helicon to attend the Decennial Mathematics Convention. He presents a paper which indicates that one could theoretically predict the Galactic Empire's future. At first, Seldon has no idea how this could be done in practice, and he is fairly confident that no one could actually fulfill the possibility. Shortly after his presentation, he becomes a lightning rod for political forces who want to use psychohistory for their own purposes. The rest of the novel tells of his flight, which lasts for approximately a year and which takes him through the complex and variegated world of Trantor. During his flight to escape the various political factions, he discovers how psychohistory can be made a practical science. It is in this novel that he meets his future wife Dors Venabili, future adopted son Raych Seldon, and future partner Yugo Amaryl.
Forward the Foundation
This novel is actually told as a sequence of short stories, just as was the case with the original trilogy. They take place at intervals a decade or more apart, and tell the story of Hari's life, starting about ten years after Prelude to Foundation and ending with his death. The stories contrast his increasingly successful professional life with his increasingly unsuccessful personal life.
In his capacity as First Minister, he gains the nickname Raven for his dire predictions of the future.