The Rat Pack is often attributed to Frank Sinatra and his entertainment pals known for their Las Vegas and film performances. But it didn’t begin with Ol’ Blue Eyes.

It began with Humphrey Bogart.

Bogie wasn’t a fan of rubbing shoulders with Hollywood folks in his free time, so he would invite his friends to his home in Holmby Hills for private parties.

“If the light over the front door was on, we were home and awake and a chosen very few could ring the bell,” Lauren Bacall recalled.

As the story goes, one night Bacall looked at the gang of friends in her living room and said, “You all look like a rat pack.”

The name stuck.

In her autobiography, Bacall wrote, “In order to qualify [for the Rat Pack], one had to be addicted to nonconformity, staying up late, drinking, laughing, and not caring what anyone thought or said about us."

The group even had an “election” to designate which role each member would play.

Frank Sinatra was pack master, Judy Garland was the first vice president, Bacall was den mother, Sid Luft was cage master, Irving “Swifty” Paul Lazar was recording secretary and treasurer, writer Nathaniel Benchley was historian, and Bogart was the rat in charge of public relations. Other members included Spencer Tracy, Katharine Hepburn, David Niven, Ira Gershwin, and restaurateur Mike Romanoff.

“What fun we had with it all! We were an odd assortment, but we liked each other so much, and every one of us had a wild sense of the ridiculous,” Bacall remembered.

However, after Bogart’s death in 1957, the original Rat Pack died too.

The second iteration of the group came thanks to Sinatra and consisted of those he kept close – Dean Martin, Sammy Davis Jr., Joey Bishop, and Peter Lawford.

At first, they were referred to as “the Clan,” a name that Davis didn’t appreciate.

“The Summit” was another nickname, and it referenced the planned summit between President Dwight D. Eisenhower and Soviet Premier Nikita Khruschchev. While Sinatra preferred this name, the name “Rat Pack” won out anyway.

The name’s re-emergence came thanks to a gossip column written by Dorothy Kilgallen when discussing John F. Kennedy’s relationship with Sinatra and his pals before he became President.

While the pack was generally thought to be a tight-knit group, since they appeared together in numerous shows and films, they actually didn’t socialize extensively outside of those events.

Still, the cool image that they exuded was enough to cement the name in pop culture history.