Who is Billy Evans, the husband of Theranos founder Elizabeth Holmes?

While Elizabeth Holmes’ spectacular fall has been pored over in countless news reports, documentaries, several books, and a TV miniseries, little is known about her marriage to hotel heir William “Billy” Evans.

The couple met in the fall of 2017 at a Fleet Week charity event in San Francisco, as Holmes’ blood-testing business Theranos was under federal investigation.

“I was captivated by her childish wonder and authenticity,” Mr Evans wrote in a gushing letter to the judge ahead of her sentencing last year.

“She listened more intently than anyone I had ever met.”

Mr Evans said that they remained friends for six months, and that he had been “hesitant to dive in” to a relationship due to unflattering reports of Holmes in the press.

“I was naturally conflicted, the person I knew did not align with the narrative others had crafted,” he said.

As Holmes’ billion-dollar tech startup crumbled around her, their relationship grew closer.

He was a constant presence during her trial, conviction and sentencing to 11 years prison on four counts of wire fraud and conspiracy to commit wire fraud in California last year.

Holmes reported to start her prison sentence at a federal prison in Bryan, Texas, on Tuesday.

Here’s what to know about Billy Evans.

Mr Evans, 30, is an heir to Evans Hotels, a family-owned hospitality group based in the San Diego area.

The business was founded in 1953 by his grandparents William and Anne Evans, and runs luxury boutique hotels, restaurants and wellness spas.

He attended the Massachusetts Institute of Technology from 2010 to 2015, and graduated with a Bachelor of Science in Economics, his LinkedIn profile shows.

Mr Evans studied Chinese language and literature at Fudan University in Shanghai, China during this time.

Mr Evans has worked at LinkedIn and Luminar Technologies, a self-driving car company, as a special projects manager, according to his LinkedIn profile.

Holmes met Mr Evans in 2017 at a charity event in the Bay Area, around the time when she was under investigation for defrauding Theranos investors.

The couple kept their relationship under wraps as Holmes was charged with fraud by the US Securities and Exchange Commission in 2018.

They reportedly got engaged in 2019, and married that year in a private ceremony. He was 27 at the time, and she 35.

In a recent New York Times interview, Holmes referred to Mr Evans as her “partner”.

Holmes gave birth to the couple’s first child, William Holmes Evans, in July 2021 while she was awaiting trial.

Mr Evans attended every day of Holmes’ nearly four-month trial in San Jose, California, last year.

The jury heard salacious details of Holmes’ relationship with Ramesh “Sunny” Balwani, Theranos’ former COO, as her defence lawyers sought to lay the blame for the company’s demise on him.

It was revealed just before her sentencing last November that Holmes was pregnant with a second child. She gave birth to her daughter Invicta in February.

Holmes was accused in court documents of conceiving the child in an attempt to avoid prison.

In a 12-page letter to judge Edward Davila ahead of sentencing, Mr Evans wrote of the profound impact the relationship had left on him, while pleading for leniency.

He shared photos of the couple hiking, sightseeing, and intimate family photos with their young son, and husky dog Balto.

“Her capacity to change the world is limitless,” he wrote in the glowing testimonial.

He said the couple had spent six months living together in a truck after their San Francisco address was made public, travelling around national parks and sleeping under the stars.

“While this nomadic life was my idea, Liz embraced the frenetic beauty of it, and we often reminisce about how it was the favorite place we ever lived,” he wrote.

“The peace and quiet out of the spotlight was refreshing. Walmart parking lots and rundown campgrounds gave us a much-needed solace.”

He also spoke in detail about the toll that the public attention had placed on Holmes, and her paranoia around going out in public.

“She walks through public places trying to hide, but it doesn’t do much good,” he wrote. “Once we were five miles down a trail in a national forest and a passerby took out their phone to snap a picture. It is incessant.”

He also said he had been ostracised by friends and family due to the relationship, and that Holmes had been punished enough.

“We sleep with our shutters closed, missing the beauty of each sunrise to help insure our privacy. This will follow us for the rest of our lives. There is no avoiding the scorn that accompanies Elizabeth Holmes.”

In one memorable passage, Mr Evans told a story about Holmes searching for 16 hours “in brambles and poison oak” after Balto was apparently carried away by a mountain lion from their front porch.

“It was only once she saw his lifeless body that she could come to realise that he was gone,” Evans writes.

“But that's Liz for you, she's constantly hoping and working towards the best outcome, even if it is unlikely.”

He pleaded with Judge Davila to sentence Holmes to a non-custodial sentence for the sake of their children.

“My heart is broken with the thought of spending any days away from Liz, for a future in which my son grows up with a relationship with his mother on the other side of glass armed by guards,” he said in his memo.

In a New York Times article published in May, reporter Amy Chozick was invited to spend time with the couple at their rental home in San Diego, on a family zoo outing, and shared meals with the family.

Mr Evans reportedly stepped in to defend his wife at the suggestion they were being dishonest about turning over a new leaf.

"Your question is, 'How do you say anything when everything you say is going to be doubted?' You just have to say it," he said.