Jean Arp (1886–1966) was an Alsatian sculptor, painter, poet and abstract artist.
We can, of course, go back a lot longer in music and language, but I think the twentieth century was all about the origins of generative art. It goes back to Marcel Duchamp. I think it goes back to the randomness of Jean Arp.
Casey Reas, Casey Reas on the History of Generative Art - Part 1