Tonight, the new FX drama Fosse/Verdon premieres at 10 p.m. ET. And while you might not have heard of Gwen Verdon or Bob Fosse, you've probably heard of the actress starring in the show: Michelle Williams. (Now, she's best known for the films Blue Valentine and Manchester by the Sea, but her first big break was on the classic TV show Dawson's Creek.)

The show is based on the real-and real dramatic-love story between Gwen Verdon (played by Michelle), a woman who is considered one of the greatest Broadway dancers of all time, and Bob Fosse (played by Sam Rockwell), who was an influential director and choreographer.

The two started out working together, but before long, fell in love-cue the drama. The fictionalized show follows their tumultuous relationship over a series of decades (think: a showbiz version of This Is Us).

While the first episode doesn't debut until tonight, the trailer is already here-and looks so freaking good

Before you tune in tonight, heres everything you need to know about these two:

They met in 1955.

Bob was encouraged to cast Gwen for the lead female role of Lola in the Broadway musical Damn Yankees. He was hesitant at first and insisted on spending a few days in a rehearsal hall together to see if he could work with Gwen, according to the official website for the pair. Apparently, they hit it off, and both went on to earn Tony Awards for their work on the show.

Bob was married when they met.

The duo reportedly fell in love while working on Damn Yankees together, but Bob was married to his second wife, dancer Joan McCracken, at the time, per ET. (Yikes.) Clearly, that marriage didn't last...

They went on to do more collaborations.

Damn Yankees was such a success that Bob and Gwen did another Broadway musical-1960s Redhead-which he directed and choreographed, and she starred in, according to Playbill. The show ended up winning six Tony Awards, so yeah, these two had a good professional ~thing~ going on. They later teamed up for the shows Sweet Charity and Chicago.

They had a child together.

Bob and Gwen eventually got married and had one child, Nicole Fosse, who is a creative consultant and executive producer on the FX show. However, Bob was a notorious womanizer and struggled with drug addiction and mental health issues, leading the couple to eventually separate but never divorce, per The Washington Post . (You'll likely see a lot of that drama play out on the TV show.)

They still worked together after they split.

The two formally separated in 1971, but were still tight, according to their daughter. "They knew they could trust each other, even when their marriage was no longer really a marriage," Nicole told ET. "It was no longer a romantic marriage, but they still had a romance together and a lifelong relationship with each other. I don't really know how that happened, but they had a lot of trust with each other and a lot of loyalty. If you exclude the bedroom part, they were loyal to each other their entire lives. They spoke every day, twice a day, on the telephone." I mean, that's kinda sweet, right?

That bond helped their work relationship survive as Gwen helped Bob with the movie version of Cabaret starring Liza Minnelli. Later, in 1975, the duo teamed up again for Chicago.

Bob died in Gwen's arms.

In 1987, Bob died of a heart attack at age 60, collapsing into Gwen's arms in Washington, D.C., according to US Weekly . Years later, in 2000, Gwen also died of a heart attack at age 75.