A new book delves into the mysteries of pizza history—specifically the origins of Motown’s most famous pie—just in time for National Detroit-Style Pizza Day on June 23.

In her book, Detroit Style Pizza: A Doughtown History, author Karen Dybis takes readers inside the restaurant kitchens that developed, fought over and sought to perfect this delectable dish. On June 23 Dybis will celebrate the launch of her book at the place where it all began: at the original Buddy’s Pizza at Six Mile and Conant in Detroit.

The book explores the pizza style’s humble origins, starting with Gus Guerra putting the first square pie in the oven at Buddy’s, as well as the later chefs who adopted the innovative recipe in their own unique way, ultimately leading to the style’s burgeoning popularity today.

Related: What are the elements of an authentic Detroit-style pizza?

“There was no question that the first pizza was made at Buddy’s, but there were a lot of different families involved in the beginning and some went off and opened their own restaurants and put their own spin on the pizza, creating this intricate web of stories and origins,” Dybis said in a press release. “It was an honor to finally untangle the web and provide Detroiters the history book they deserve on the beloved pizza style.”

Buddy’s Pizza started out in 1946 as a speakeasy called Buddy’s Rendezvous. Using a bit of ingenuity, Guerra, along with other Buddy’s Pizza employees, created the first Detroit-style pizza, a square-shaped pie that was the first of its kind in a world of round pizza. Since then, Buddy’s has grown to 22 locations across the state of Michigan, and the innovative style has spread across the globe.

“We’ve always been proud of our pies and to be the place where it all started, but Detroit-style pizza wouldn’t be where it is today if it weren’t for all the Detroiters who have spread the word to create this incredible following,” said Wes Pikula, chief brand officer of Buddy’s Pizza and a 48-year veteran of the company. “It’s remarkable to think how one creative day in the kitchen could change pizza as we know it and have such a great impact on the industry. It’s been an honor to watch the growth of the pizza style, and we’re grateful for the community’s support along the way.”

In honor of National Detroit-Style Pizza Day, Buddy’s is donating $1 from every pizza sold at all 22 locations to The Salvation Army. Customers can also donate to The Salvation Army during June when they place an online order.

Buddy’s founded National Detroit-Style Pizza Day in 2021 to celebrate its 75th anniversary and commemorate the company’s role in creating the iconic pizza style. The national day allows Detroit-style pizzerias across the nation to honor the history, style and roots of where it began. It also offers an opportunity for other pizzerias to debut a Detroit-style pizza on their own menus, whether as a permanent new item or a limited-time offer to test customer response.

June 23 is also known as Buddy’s Pizza Day in Detroit, which was recognized by former Detroit Mayor Dave Bing and the Detroit City Council to credit Buddy’s Pizza for putting the city on the world’s pizza map and showcasing the city’s innovation.