When people think of Shameless, they think of William H. Macy as Frank Gallagher, and understandably so: It was on Showtime for more than a decade, became one of television’s most beloved dramedies, and, with 11 seasons and 134 episodes, remains the longest-running scripted original drama in the network’s history. But what many viewers might not realize is that Shameless wasn’t an original American creation, and Macy wasn’t the first Frank Gallagher.

The series was actually adapted from a British show of the same name that premiered back in 2004. Created by Paul Abbott, the UK version also follows the dysfunctional Gallagher family and shares many similar storylines, at least early on. It even ran for the same number of seasons, and with five more episodes to boot. Much like The Office, Shameless is one of those rare American remakes that began as an imitation of its predecessor but ultimately evolved into its own distinct thing.

The Original ‘Shameless’ Was a Phenomenon In Its Own Right

Years before we met the Gallaghers on Chicago’s South Side, there were the Gallaghers living on the fictional Chatsworth council estate in Manchester, England. The original Shameless debuted on Channel 4 in 2004 and drew heavily from Abbott’s own upbringing in a working-class family. Like its American successor, the series revolved around alcoholic patriarch Frank Gallagher and his six children forced to raise themselves in the face of poverty, crime, romance, and the everyday absurdities of life.

The British version quickly became one of Channel 4’s top series. Critics praised its willingness to tackle serious social issues without sacrificing its dark sense of humor, and it even earned the BAFTA Award for Best Drama Series in 2005. It’d go on to air 139 episodes through 2013. That kind of success naturally caught Hollywood’s attention. And at first, HBO was the one who wanted it. The network ultimately passed on it, though, at which point producer John Wells took the project to its eventual home: Showtime.

Given the success of the original series, it’s not surprising that some of the American take’s earliest episodes are incredibly similar to their British counterparts. Entire scenes, character introductions, and story beats were recreated almost verbatim. Frank was still the same old deadbeat, Fiona was still serving as the family’s surrogate parent, and kids Lip, Ian, Debbie, Carl, and Liam all filled familiar roles to Abbott’s version, as well. But from Season 2 on, Shameless started to differentiate itself in small ways, which eventually built to big departures.

By Their Series Finales, Both Versions of ‘Shameless’ Stood Apart

By the later seasons, Shameless was no longer adapting Abbott’s scripts. It had become its own sprawling ensemble drama with distinct characters, relationships, and themes — most notably, the way the Gallaghers stuck around for much longer on the U.S. version compared to the UK source material. Perhaps no character illustrates that evolution better than Fiona Gallagher. Emmy Rossum transformed Fiona into the emotional center of the show, carrying storylines about guardianship, relationships, addiction, entrepreneurship, and personal responsibility for over a hundred episodes in total before her eventual departure. Meanwhile, in the British version, Fiona left at the end of Season 2. Frank, too, evolved beyond his British counterpart. Macy still plays Frank as a selfish, manipulative, and frequently irredeemable guy, yet Macy managed to find more moments of vulnerability that made viewers understand (if never fully forgive) the character better than the British version.

American remakes often struggle to justify their existence. Many never shake comparisons to the originals, while others are canceled before finding their footing. Rather than trying to outdo the British series at its own game, however, Shameless tackled the class divide and other realities of American life, including healthcare, policing, addiction, student debt, economic inequality, and housing insecurity. While the original Shameless deserves enormous credit for creating one of television’s most memorable dysfunctional families, the American version actually accomplished something even rarer: it honored its source material while still managing to do something uniquely its own. That’s what ultimately makes it one of the best U.S. remakes of British TV.