Orson Welles made a "groundbreaking" TV pilot in 1958 with the help of Lucille Ball and Desi Arnaz

The New Yorker

When Welles arrived in Hollywood in 1939, the first movie he planned to make wasn't Citizen Kane, but a mystery called Smiler with a Knife. Welles wanted Lucille Ball, a then-20-something RKO contract actress, to be his co-star. But the studio turned her down. "A decade and a half later," says Richard Brody, "Welles was severely struggling to sustain a career; forty-one years old, he was famous as an actor but his directing career had been thwarted by producers’ unwanted recuts of his films and by poor box-office results. Ball had become a TV star and mogul, both starring in and producing (with her then husband, Desi Arnaz) I Love Lucy, which was on the air from 1951 to 1957 and made her both famous and very, very rich. When Welles’s Hollywood career was nearly nonexistent, he turned to television, and Ball and Arnaz, who by that time had the power and the money, turned a share of both over to Welles for his effort to establish himself there. Only one episode of the resulting project was ever filmed, the pilot, titled The Fountain of Youth (it’s streaming on YouTube), and it’s as artistically original for television as Citizen Kane was for the movies, and—at least in part—for a very similar reason...The story is both pleasantly seamy and inconsequential, as pat and flimsy as a mad-science soap opera. Its psychological dimensions are infinitesimal; its social context is nonexistent. But what Welles makes of the story is—or, rather, should have been—a template for what the art of television could have become."