The 37-year-old actress surprised the world on Wednesday when she revealed to Vanity Fair that she secretly married Phil Elverum in the Adirondacks in upstate New York this month.
Now, ET's breaking down everything you need to know about the 40-year-old indie musician.. and what makes their relationship so "sacred" and "special."
1. He kicked off his musical career in the '90s.
Back in 1996, Elverum performed as a frontman for the rock band The Microphones until 2003. He was the band's principal songwriter and producer, taking their music from Olympia, Washington, to tour shows in North America and England.
He later adopted the moniker Mount Eerie in 2004, releasing an impressive nine studio albums (and 13 EPs) since then, including the critically acclaimed A Crow Looked at Me and his latest, Now Only.
2. He changed the spelling of his last name.
Around the time he decided to record under his new persona, the talented musician also made a slight change to his real-life name. His original surname was Elvrum, but he later added an extra 'e' to its spelling.
"Mount Eerie is a new project. The Microphones was completed, or at least at a good stopping point. I did it because I am ready for new things. I am new," he said in 2003, in an interview with CITR-FM's Discorder.
3. He loves his hometown -- and the outdoors.
Elverum was born and raised in Anacortes, Washington, which is a small town on Fidalgo Island. Give his music one quick listen, and you'll understand just how much love he has for the little things in life, like nature and the place he grew up.
4. Elverum moved across the country to be with Williams.
In her VF tell-all, Williams reveals that her husband packed up his home in Anacortes this month to be with her in Brooklyn, New York. The two now live together, and it appears Williams couldn't be happier.
"Ultimately the way he loves me is the way I want to live my life on the whole," she gushes. "I am finally loved by someone who makes me feel free."
5. He also lost a loved one.
From 2004 to 2007, Williams was in a relationship with Heath Ledger. She gave birth to their only child together, daughter Matilda, in October 2005, a few years before the actor tragically died in January 2008.
Elverum also has one daughter, Agathe, from his previous marriage to Canadian artist and musician Geneviève Castrée, who died in 2016 after she was diagnosed with stage IV pancreatic cancer one year prior. Many of his emotional lyrics touch on the heartbreak he felt after losing his "person."
6. Elverum helped Williams believe in love again.
Williams, who has been notoriously private about her love life, told Vanity Fair that the reason she decided to finally open up about her newest relationship was in hopes that other women would feel inspired by her story.
"I don’t really want to talk about any of it," she says. "But there’s that tease, that lure, that’s like, 'What if this helps somebody? What if somebody who has always journeyed in this way, who has struggled as much as I struggled, and looked as much as I looked, finds something that helps them?'"
"I never gave up on love," she continues. "I always say to Matilda, 'Your dad loved me before anybody thought I was talented, or pretty, or had nice clothes.'"