Everybody knows Lucille Ball, Desi Arnaz and the legend of “I Love Lucy.” But do they really?

There have been several movies over the years about the two icons, including Aaron Sorkin’s recent “Being the Ricardos.” But the story of “Lucy and Desi” goes far beyond the smash success of “I Love Lucy,” and that’s what got Lucie Arnaz — the daughter of the late Hollywood icons — thinking about doing something bigger. Arnaz has partnered with former NBC Entertainment and WarnerMedia Entertainment chairman Bob Greenblatt to develop what they envision as a three-season deep dive into the lives of Ball and Arnaz, from the couple’s separate tumultuous upbringings to making TV history with “I Love Lucy” — and then the clashes that led to their eventual divorce.

Arnaz and Greenblatt have recruited Oscar nominee and Emmy winner Richard LaGravenese (“The Fisher King,” “Behind the Candelabra”) to create the series, which will rely on source material including autobiographies written by Ball and Arnaz, the rights of which have reverted to Arnaz. Greenblatt’s The Green Room and Arnaz’s Desilu Productions are behind the project, which will also be produced by Green Room content head Jon Wu.

“If you’re really willing to look at the whole thing, there’s quite a story there, and a lot to be learned,” Arnaz said. “It’s very emotional, and it’s not what people think. It’s not just all about ‘I Love Lucy.’”

Arnaz and Greenblatt have put together a pitch deck for the series, with the working title “Lucy and Desi: The Greatest Story Never Told,” and plan to start meeting with networks and streamers in the coming months. The timing of the pitch comes as “I Love Lucy” celebrates its 75th anniversary in 2026 (the show debuted in October 1951) and on the heels of two new books exploring the couple: “Desi Arnaz, The Man Who Invented Television,” by Todd S. Purdum, and Arnaz’s own new look at her parents’ relationship, “Lucy & Desi: The Love Letters,” which she edited.

“As we take it to buyers, there’s a version of this that could be 10 hours and done, if somebody wants to jump in with that,” Greenblatt said. “But we want to present it as a multi-season show. We think it’s three seasons of eight episodes. Obviously, we have to find the right buyer and cater to what they want to do. But it needs to have time to breathe. It really is an extraordinary story, from when they’re each teenagers in their separate worlds — one being Cuba as it’s coming apart at the seams, and one being very WASPy New York. They were both thrust out on their own, quickly at a young age, to try to figure out who they were and find their way in the business. Then they converge in 1940 on a soundstage at RKO, doing a movie together. ‘I Love Lucy’ is 11 years later, but that’s 11 years when they’re together in a marriage that’s up and down and complex.”

Arnaz and Greenblatt were inspired by the timeline of Netflix’s “The Crown” to similarly divide “Lucy and Desi” into different eras. In their pitch, Season 1, “From Cuba and Jamestown to New York and Hollywood,” would focus on 1930 to 1940; Season 2, “Family Life, B-Movies and Radio,” would span from 1940 to 1951; and Season 3, “The Ricardos Catch Fire, and Beyond,” would look at the “I Love Lucy” era, from 1951 to 1960 and more.

In partnering with LaGravenese (who most recently penned Paramount+’s upcoming “Unspeakable: The Murder of JonBenét Ramsey”) and not a comedy writer, Arnaz said it was important to explore some of the darker aspects of her parents’ relationship in addition to the good times.

“The story is not all ha-ha. There’s a lot of sadness, there’s addiction, and there’s cheating, and there’s lots of fights for no reason,” she said. “There’s something to be learned from what they went through and how it’s not that easy to have it all… They had this wonderful legacy, which just happens to be the funniest show ever. But they’re more than that show. Their lives, individually and collectively, were very exciting and amazing and deep. Finding the right writer was hard because most people might think that, because we’re doing the story of Lucille Ball and Desi Arnaz that it’s going to be really funny. And it’s going to have great kinds of humor in it. But it’s not ‘I Love Lucy.’ It’s not a sitcom. Everybody says, ‘your father invented television,’ but in reality, that’s not at all what he was trying to do. They were just trying to stay together, and do a show.”

Arnaz and Greenblatt first collaborated when he produced a 40th anniversary reunion concert benefit for “They’re Playing Our Song,” the musical that served as her Broadway debut. Around the same time, Arnaz was an executive producer on “Being the Ricardos,” but ultimately that film focused mostly on one moment in time in the Lucy/Desi relationship — and so, Arnaz brought the idea of a much broader look at her parents to Greenblatt, and they started collaborating on what would become this series pitch.

“Lucie has this ability to separate herself from being in the middle of it and really see it from an objective point of view,” Greenblatt said. “She’s the first person to say, ‘we want to do it warts and all, and we don’t want to just whitewash it and protect everybody.’ It really is complex. Can we get underneath the causes and the reasons for the way they were. We all think they’re the Ricardos. There’s a part of them that’s who they were, but that’s so little of the full picture.”

LeGravenese entered the picture when Arnaz and Greenblatt went looking for somebody who could balance the comedy of “I Love Lucy” with the drama of what happened behind the scenes.

“Richard came to mind, as he’s got this great background in writing feature films prominently for most of his life and more recently television,” Greenblatt said. “I love his ‘Behind the Candelabra’ movie, for which he won the Emmy. When we presented the idea to him, he just lit up. He’s like, ‘Oh my God, I’ve loved these two people as a fan, and I’ve gone down the rabbit hole on the internet many times.’ He just knew a lot about the story already. Then we all met, and Lucie met him, and he just felt like the right guy.”

Added Arnaz: “There’s been now two TV movies and a feature film and my documentary, but none of those other films ever looked at, ‘OK, that happened and that happened, but why? Why did he do that? Why did she respond that way?’ I wanted to correct that. If nothing else, I wanted to be able to look at them as people and say, ‘aren’t they interesting? Imagine, even with all that sorrow and all that loss, he was able to do this. And then he had to drink. Well, why did he have hookers? Why did that happen?’ And so if we can show the early and go all the way to the end, in some way, we might be able to help people understand them even more.”