Majorie Eaton played Emperor Palpatine in the original version of The Empire Strikes Back.
Eaton, who died in 1986, worked as an actress from the mid-1940s to the mid-1980s. She appeared in the films Mary Poppins, Witness for the Prosecution, That Forsythe Woman and the TV series Alfred Hitchcock Presents and The Lone Ranger.
If you’ve read J.W. Rinzler’s book The Making of Star Wars: The Empire Strikes Back you know that Rinzler wrote that while Eaton filmed scenes of the Emperor she was replaced by Elaine Baker. Years later Lucasfilm Story Group member Pablo Hidalgo talked about this confusion on Twitter and appears to confirm that Baker was NOT seen as the Emperor on the screen. You can see a screenshot of this conversation on Eaton’s Wookiepedia page.
The voice of the Emperor was provided by Clive Revill. Ken Ralston from ILM talked about how the Emperor was brought to screen in The Making of Star Wars: The Empire Strikes Back.
To make the hologram of the Emperor, we shot an actor in makeup with the eyes blacked out. We would up shooting the eyes of a chimpanzee, then matchmoving the eyes of the actor and rephotographing it from a TV screen.
Here’s footage of Eaton as the Emperor. The special edition of The Empire Strikes Back replaced Eaton’s footage and footage with Ian McDiarmid.