In the summer of 2013 I interned at the Leo Burnett advertising agency’s corporate library and archives. In the course of my work I came upon boxes of original conceptual artwork and copy from the 1950s and ’60s of the famous brands Leo Burnett created: the Marlboro Man, the Jolly Green Giant, the Pillsbury Doughboy. They also created several of Kellogg’s famous clan of characters: Tony the Tiger, Snap Crackle and Pop, Toucan Sam. At the time I marveled at these artifacts merely as a student of history and consumer familiar with these characters. But now, having read Howard Markel’s new book The Kelloggs: The Battling Brothers of Battle Creek, I see those characters not as the foundation of the Kellogg’s brand, but, since they were created after both Kelloggs died, as its unintentional consummation.

If you’re like me, you:

(a) didn’t know there was more than one Kellogg;

(b) didn’t know one of them was John—a renowned doctor in his time (1880s-1940s), founder of the Sanitarium in Michigan, and “better living” proponent who was way way ahead of his time on dangers of prolonged sitting, meat consumption, smoking, and the benefits of exercise—and the other was Will, John’s long-suffering younger brother, dour millionaire magnate of the Kellogg cereal line we all know (that’s his signature on the box); and

(c) didn’t know they hated each other’s guts.

Markel covers a lot of ground in this family biography. On one hand this provides readers with a backstory I suspect most haven’t heard before, like how the Kelloggs were reared in an apocalyptic Seventh-Day Adventist culture that valued health reform and that bankrolled the Sanitarium in Battle Creek that sprung John to global renown. John was the idea man, the charismatic physician into what would now be called alternative medicine, and (let’s be honest) overbearing asshole. Will, conversely, was the details man, adept business manager, and John’s put-upon lackey before he set off on his own to expand his cereal empire and his bitterness toward John. (He was also an overbearing asshole.) Because of long-held resentments and their similar products with the same last name, the brothers sued each other throughout the 1910s and never reconciled, even into old age.

On the other hand, Markel covers so much ground and in a sometimes scattershot way that it can be an exhausting read. As a physician and medical historian himself, Markel shines in the parts about John’s development as a doctor and how it influenced his products. He illustrates the cruel irony of brothers so focused on creating products and principles based on health and “better living” for others feeding a most unhealthy rancor towards each other. He also ably balances the brothers’ colorful back-and-forth over the years, thanks to an abundant written record at his disposal. But the parts about the inner workings of the businesses get repetitive and wearying, and the last few chapters—tackling the post-litigious years and John’s unfortunate promotion of eugenics—feel tacked on when they could and should have been better integrated into the narrative, which is as a whole chronologically discombobulating.

Nevertheless, this is an illuminating portrait of a foundational American family and their business empire. Though not quite a tragedy in the end, given the Kellogg Foundation’s continued charitable work (thanks to Will leaving his millions with them after alienating all his progeny), it is a grim reminder of the power we waste on hatred and how wealth can’t cure, in Markel’s words, a “damaged soul.”