In the 21st century, we are no longer content to have merely franchises or sequels. Nowadays, everything has to leap from a single pop culture entity to a sprawling cinematic universe. Marvel, DC, Star Wars, monsters, the CW’s Arrow-verse, Transformers, Harry Potter, Sheldons old and young–even the city of Chicago has its own lineup of TV dramas!

If you think this aggressive brand extension is unique to our post-Iron Man world, think again. The sitcoms of the 20th century engaged in shared universe tactics before we had a term for them, with many shows established as all co-existing in the same reality via character crossovers (seriously, google “Tommy Westphall Universe” and prepare to waste hours of your day).

You probably didn’t realize it at the time, but all of this applies to TGIF. Hulu just added five shows from ABC’s classic Friday night lineup (Perfect Strangers, Full House, Family Matters, Step By Step, Hangin’ with Mr. Cooper), and you may be surprised to learn that they are all connected. That’s over 800 episodes of TV (and almost 13 days worth of content!) for you to wade through, so why not start with the episodes that laid the foundation for one of the most heart-warming shared universes of all time? Here are the major moments in the TGIF-verse, when titans like Steve Urkel, Michelle Tanner, and John Stamos (yes, the actor) clashed.

1 'Perfect Strangers' & 'Family Matters' Episode: “All the News That Fits” (s3.e1)

Airdate: September 23, 1987

Crossover Character: Harriette Winslow It all began innocently enough, with a single elevator operator working in a newspaper building in Chicago. Jo Marie Payton debuted as the straightforward Harriette Winslow in Perfect Strangers‘ Season 3 opener, when Larry (Mark Linn-Baker) got a job at the Chicago Chronicle. Even though she was just a supporting character, Harriette became an essential part of Perfect Strangers, and in this episode, she plays a pivotal role in getting Balki (Bronson Pinchot) a gig at the Chronicle with Larry. Watch the Perfect Strangers episode "All the News That Fits"

2 'Perfect Strangers' & 'Family Matters,' Again Episode: “Crimebusters” (s4.e12)

Airdate: January 20, 1989

Crossover Character: Carl Winslow Harriette Winslow appeared in 33 episodes across Perfect Strangers’ third and fourth seasons, and the show expanded her world by introducing her police officer husband Carl (Reginald VelJohnson). The Season 4 episode “Crimebusters” helped further the cause for the Winslow’s spinoff by casting the immediately lovable (and sometimes intense) VelJohnson as Harriette’s husband. In Carl’s only Perfect Strangers appearance, hungry-for-an-exclusive Larry trails Carl under the assumption that he’s going to make a big bust. After Carl’s debut, a spinoff was a no-brainer. Family Matters, a show initially focused on Harriette and Carl’s family, debuted 8 months after this episode aired. Balki and Larry were originally supposed to appear in the pilot, but their involvement was cut early. Neither character ever appeared on Family Matters, which is probably why no one thinks of the show as a spinoff. And if you know Family Matters, you know the show didn’t focus on Harriette and Carl for very long. Watch the Perfect Strangers episode "Crimebusters"

3 'Full House' & 'Family Matters' Episode: “Stephanie Gets Framed” (s4.e16)

Airdate: January 25, 1991

Crossover Character: Steve Urkel By the end of Family Matters‘ second season, the show had a new lead character: Steve Urkel (Jaleel White). Urkel was so popular that his presence was demanded on other ABC sitcoms, including the massively popular Full House. Urkel’s appearance on Full House is akin to Captain America, Thor, and Iron Man all slugging it out in Marvel’s the Avengers. Urkel annoys DJ (Candace Cameron), he pesters Uncle Jesse, and he finds common ground with Full House scene-stealer Michelle (Mary-Kate and Ashley Olsen). He even plays a pivotal role in the episode’s A-plot, as he helps Stephanie (Jodie Sweetin) adjust to her new glasses. Watch the Full House episode "Stephanie Gets Framed"

4 'Step By Step' & 'Family Matters' Episode: “Brain Over Brawn” (Family Matters s3.e2)/”The Dance” (Step By Step s1.e2)

Airdate: September 27, 1991

Crossover Character: Steve Urkel Urkel’s media dominance continued into the following TV season, and the character was used to ensure that viewers checked out TGIF newbie Step By Step. As it was originally broadcast, the end of the Family Matters episode “Brain Over Brawn” saw Urkel propelled into the atmosphere by a jetpack. He then touched down a minute later in the show following Family Matters in the TGIF lineup, Step By Step. Yep, Steve Urkel flew from Chicago to Washington, Wisconsin during a commercial break. Urkel continues his crusade to assist the middle daughters of sitcoms by cheering up tomboy Al (Christine Lakin) after she gets dumped before the school dance. If you forgot just how popular Urkel was in 1991, this is the episode to watch. Not only does the episode bend over backwards to facilitate an Urkel cameo, it includes a “Do the Urkel” dance number that features the original song “Do the Urkel Dance.” Even more bewildering? This entire song and dance number originally appeared in a Family Matters episode (“Life of the Party”) from earlier that year. Wasn’t life better when sitcom characters got to have their own dance crazes? And for all you Urkel completists out there, you’ll want to check out the Step By Step Season 7 episode “A Star is Born,” which features a two-second cameo from Steve. Watch the Step By Step episode "The Dance"

5 'Hangin' With Mr. Cooper' & 'Full House' Episode: “Hangin’ with Michelle” (s1.e2)

Airdate: September 29, 1992

Crossover Characters: Michelle Tanner and Uncle Jesse Just like with Step By Step a year earlier, newbie Hangin’ with Mr. Cooper brought in another show’s breakout character to ensure people would stick around for episode two. This time around, though, a different character had achieved cultural omnipresence: Michelle Tanner. As soon as the Olsen twins were old enough to talk, the Full House writers were giving her catchphrase (“You got it, dude!”) after catchphrase (“Oh puh-lease!”) after catchphrase (“You’re in big trouble, mister!”). By the start of Season Six, Michelle wasn’t old enough to cross the street, but she was old enough to crossover to another show. Since both Cooper and Full House were set in San Francisco, Michelle didn’t need a jetpack to hang with Mark Curry. Mark, an NBA player turned substitute teacher, meets Michelle when he takes a job at her elementary school. That means we also get a crossover appearance from Michelle’s bestie Denise and everyone’s least favorite kid, Aaron (ugh, Aaron). Things get dangerous when Michelle accidentally causes Mr. Cooper to injure himself. She apologizes with a song that pushes the limits of the TV-G rating. As if all that wasn’t enough, there’s even an appearance from Uncle Jesse where he shares haircare techniques with Mark’s roommate Vanessa (Holly Robinson-Peete). Watch the Hangin' with Mr. Cooper episode "Hangin' with Michelle"