One of the last great rulers of the
Galactic Empire, also last of the Entun Dynasty, according to
Isaac Asimov's
Foundation series. Cleon's legacy is one of benevolence and inaction.
Cleon I is most notably remembered for his sponsorship of psychohistory. Under the direction of Eto Demerzel, Cleon I invites Hari Seldon to the Imperial Palace on Trantor to see if psychohistory can be manipulated in order to strengthen his rule. Seldon is adamant that psychohistory is a fledgling science at best and is of no use to Cleon.
Demerzel later retires after a scandalous claim that he is a robot, and Cleon chooses Seldon as his replacement. Under Seldon's administration, psychohistory is advanced.
Cleon I is assassinated by the First Gardener, Mandell Gruber, in an attempted overthrow by the Joranumite Conspiracy. Also involved in the attempt are Seldon himself, Manella Dubanqua, Raych Seldon, and Gambol Denn Namarti.