Stefani talked about her love with founding No Doubt member Tony Kanal and how her heartbreak shaped the record that launched her decades-long career, 1995's Tragic Kingdom.
Then came her seemingly fairytale romance with Bush frontman Gavin Rossdale.
"The the next chapter. I meet Gavin, right? And that was it," Stefani said.
The couple, who married in 2002, seemed poised to survive – even by Hollywood standards – but news of their split came in Feb. 2015, 11 months after the birth of their third child.
"Everybody knows what happened next," she says referring to the alleged affair between Rossdale and the family's nanny.
During that time Stefani had taken up residence in one of the big, red judges chairs on the singing competition show, The Voice. Rather than let heartbreak derail her, Stefani again used it to propel her forward, throwing herself into the show and into her newest record, This Is What The Truth Feels Like, which spawned her only number-one solo hit, "Used to Love You."
"It went from horrible to, like, hopeful and, like, 'Wow, God, you just don't know what's gonna happen next.'"
The August issue of Harper's Bazaar is on newsstands July 19.