SPOILER WARNING
Eto Demerzel was just one of the many alter-egos of R. Daneel Olivaw. As Demerzel, Daneel was able to be the original First Minister to the emperor Cleon I. As the first minister, Daneel was able to manipulate certain events to his benefit, such as his first meeting with Hari Seldon under the guise of a trantorian reporter named Chetter Hummin (a play on the word human), therefore establishing a friendship with him, and essentially forcing Seldon to continue forward with psychohistory. Demerzel/Daneel, with the help of Seldon and his foster son Raych Seldon, was able to thwart the first Joranumite conspiracy. Following his resignation from his post, Demerzel was never seen again until Hari Seldon's Funeral in the year 12,069 G.E., or 1 F.E.