First developed 80 years ago as “Rowntree’s Chocolate Crisp,” the Kit Kat bar has become a staple in grocery and convenience stores the world over. And while the marketing slogans and catchy jingles have changed over the years, that shareable chocolate-and-wafer design hasn’t. So take a break from whatever you’re doing and indulge in a few facts.

1. THE NAME ORIGINATED IN THE 17TH CENTURY.

Founded in the late 1690s, London’s Kit-Cat Club was a gathering of Whig party supporters and literary minds that met regularly at a pie shop on Shire Lane. The owner, Christopher Catling, specialized in making meat pies that everyone called “kit cats,” after an abbreviated version of his name. Fast-forward two centuries when Joseph Rowntree, co-founder of the Rowntree’s candy company, zeroed in on the name and secured the title trademark in 1911. It’s not clear whether the famous club directly influenced Rowntree or not (or whether the popular Kappa Alpha Theta myth—that Rowntree’s wife was a sorority member, and the name was an endearing acronym for Keep In Touch, Kappa Alpha Theta—had any part). In any case, the term “kit kat” had seen a resurgence in jazz age London. There was a Kit Kat nightclub at the time, as well as a Kit Kat band that drew regular crowds.

2. IT WAS ORIGINALLY A BOX OF CHOCOLATES.

After trademarking the names “Kit Kat” and “Kit Cat” in 1911, Rowntree proceeded to sit on them for a decade. In the 1920s, he came out with boxes of chocolates called Kit Cat that appeared on shelves for several years before being discontinued. In 1935, Rowntree’s introduced a chocolate wafer divided into four sections, or “fingers,” and called it Rowntree’s Chocolate Crisp. Two years later, the company changed the name to Kit Kat Chocolate Crisp.

3. IT WAS MADE TO ACCOMPANY PACKED LUNCHES.

The Kit Kat’s unique square-ish shape came about because Rowntree’s wanted to make a bar that workers could stuff inside their lunch sacks. An employee at Rowntree’s proposed the idea: “A chocolate bar that a man could take to work in his pack up (packed lunch).” The company developed the shape, further distinguished it by dividing it into four sections, and wrapped it all inside bright red packaging.

4. AND TO GO WITH A CUP OF TEA.

In an age when candy bars were often promoted as meal replacements, Rowntree’s marketed Kit Kat bars as “the biggest little meal.” To appeal to those who preferred it as a snack, Rowntree’s also came up with the slogan “the best companion to a cup of tea.” That concept of taking a tea break would help inspire an even more effective slogan in later years.

5. THE WRAPPER WAS BLUE FOR FIVE YEARS.

During World War II, a shortage of milk forced Rowntree’s to switch from milk chocolate to dark chocolate in its Kit Kat bars. To signify the change, the company changed the wrapper from red to blue and dropped “Chocolate Crisp” from its title. They also offered a somber, spin-free message to customers: “Because no milk can be obtained for chocolate manufacture, the Chocolate Crisp you knew in peace-time can no longer be made. Kit Kat is the nearest possible product at the present time.”