All About Charles Simonyi, the Microsoft Billionaire Who Quietly Dated Martha Stewart for 15 Years (Including While She Was in Prison)

Martha Stewart and Charles Simonyi were romantically linked for 15 years, from 1993 to 2008

Martha Stewart and Charles Simonyi — the man behind Microsoft Word and Excel — made quite the power couple when they dated in the 1990s and early 2000s.

The two formed a friendship in the early 1990s, following the end of Stewart’s 30-year marriage to publisher Andrew Stewart. At the time, Simonyi was the chief architect at Microsoft and was responsible for the creation of some of the company’s most successful software. Stewart, meanwhile, was in the midst of growing her lifestyle empire, which eventually became Martha Stewart Living Omnimedia. The company would make Stewart the first self-made female billionaire in the United States — and Simonyi was by her side as it happened.

Though the duo were always coy about their official relationship status, Simonyi also stood by Stewart as she faced criminal and civil charges for lying about a stock trade. They remained together while she served her five-month prison sentence, and resumed their romance upon her release in March 2005. But in 2008, after nearly 15 years together, Stewart and Simonyi split for good.

Related: Who Is Martha Stewart's Ex-Husband? All About Andrew Stewart

In the Netflix documentary about her life, titled Martha, Stewart called Simonyi a "total genius" and referred to their breakup as her “second divorce."

“If I analyze my life, I think the work has taken precedence over the romance,” Stewart told E! News about her love life in 2023. “I have a hard time making room for both and it's not the highest priority that I have a boyfriend, but it would be nice.”

Here is everything to know about Martha Stewart's former longtime partner, tech billionaire Charles Simonyi.

Simonyi was born and raised in Hungary

Simonyi was born in Budapest, Hungary in 1948. His father, Károly Simonyi, was an award-winning engineering professor and physicist, while his mother, Zsuzsa, was a language teacher, according to the Seattle Times.

“Our childhood, especially before ‘56, was very pleasant,” Simoyi said in a 2023 interview about growing up in then-Soviet-controlled Hungary. “It was a good life. We were surrounded by books.”

However, as Simonyi became a teenager, he sought to broaden his horizons beyond Hungary. When he was 17 years old, he left the country on a short-term visa to work as a programmer in Denmark. From there, Simonyi made his way to the United States in 1968, where he studied engineering, math and computer science — first at the University of California, Berkeley and later at Stanford, where he earned his Ph.D.

“My dream was to get out of Hungary, go to the West and be free,” Simonyi told reporters in 2006 about his childhood aspirations, per the Seattle Times.

Simonyi was one of the earliest employees at Microsoft

In 1981, Simonyi left his job at Xerox’s Palo Alto Research Center for a start-up called Microsoft. He became the company’s 40th employee, according to Forbes, and was hired by Bill Gates to develop software applications.

Simonyi spent the next two decades at Microsoft, leading the teams that created the Microsoft Office applications — including Word and Excel, The New York Times reported. During his tenure at the company, Simonyi rose to be one of its most senior employees, holding the title of chief architect for 12 years.

Simonyi left Microsoft in 2002 to start his own software company, Intentional Software Corporation, which focused on creating platforms for productivity apps. In 2017, he returned to Microsoft when he sold Intentional Software to the tech giant for an undisclosed sum.

Simonyi and Stewart were first publicly linked in 1997

Stewart, who divorced her first husband, Andrew Stewart, in 1990, began a friendship with Simonyi in 1993. The duo sparked romantic rumors, however, in 1997, when Simonyi first spoke publicly about the media mogul to the Seattle Times.

“Martha and I are good friends,” Simonyi told the outlet, per New York Magazine. “We discuss modern architecture, modern art, and the coming cyber-economy.”

Though Simonyi referred to Stewart as his “friend,” the supposed couple were frequently spotted attending events together. The two went to a White House dinner together for the Hungarian president in June of 1999 and, one month later, were seen at film producer Joel Silver’s wedding in Venice as each other’s date, according to New York Magazine.

"We started to go everywhere together. It was a different kind of life," Stewart said in Martha of the beginning of her relationship with Simonyi. "He had his own jet, he was building a boat in Germany and I started working on the boat with him."

Stewart and Simonyi’s rumored relationship continued to heat up in the early 2000s. During that time, Stewart spoke openly about traveling on Simonyi’s 230-foot yacht, according to The New Yorker, and also paid several visits to his $10 million home in Medina, Wa. — which she was reportedly helping him remodel.

“She travels in many areas in search of ideas and style and yes, she visited this area many times,” Simonyi explained to the Seattle Times.

Simonyi stood by Stewart’s side during her 2004 trial

During Stewart’s highly publicized 2004 trial — where she faced criminal charges for allegedly lying about a 2001 stock trade — email correspondence with her rumored boyfriend, Simonyi, made its way into evidence. Prosecutors presented an email Stewart sent Simonyi in September 2001, where she wrote “imclone is great — sam did pull off a coup,” according to the Seattle Times — referencing the stake she had (and later sold) in ImClone Systems and the company’s CEO, Sam Waksal.

Despite Simonyi’s mention in the criminal fraud trial, the tech billionaire stood by Stewart throughout her case and eventual conviction. When she was found guilty of conspiracy, obstruction and two counts of lying to federal investigators, Simonyi told the Seattle Times that it was a “sad day” for the lifestyle entrepreneur — and that he disagreed with the verdict.

“I do feel she’s obviously being made an example and I don’t think that’s made very clear by, for example, the U.S. attorney,” he said to the newspaper.

Despite outside appearances, Stewart said in Martha that Simonyi only visited her once during her sentence and did not "like hanging out with somebody in jail." The documentary included a letter from Stewart to Simonyi which read in part, "I've not got an email or even a note from you for so long. I'd love to hear from you."

Stewart added in the documentary, "He was out on his boat floating around the world and that was distressing to me." When she was released in March 2005, Simonyi reportedly sent a private jet to fly her from West Virginia, where she served her sentence, to her home in Bedford, N.Y., according to the New York Daily News. That October, Stewart appeared to confirm their relationship status during an appearance on Don Imus’ radio show.

“Is there anyone in your life?” the radio host asked, to which Stewart replied, “Yeah, a really nice guy who stuck by me.”

Stewart supported Simonyi when he traveled to outer space in 2007

Simonyi has made two trips to the International Space Station as a space tourist — and Stewart was by his side as he embarked on his first mission in 2007.

Prior to making his first venture into space, Simonyi consulted several trusted individuals, including his mother and brother, his former Microsoft coworkers Gates and Paul Allen, the first astronaut to walk on the moon, Neil Armstrong, and his rumored girlfriend Stewart, according to the Seattle Times. All were supportive of his endeavor to be the “first nerd in space,” including Stewart.

The cookbook author went as far as to travel to Kazakhstan in April 2007 to witness Simonyi’s launch, The New York Times reported. She also selected the meals he would dine on upon arrival at the ISS — quail, duck breast and a semolina cake, all prepared by French chef Alain Ducasse — and filmed his takeoff for her daytime television show.

“A trip to outer space is actually, for someone like Charles, a logical step,” Stewart told The New York Times, while also describing Simonyi as “intrepid, inquisitive, curious and actually very bold” for pursuing the $25 million venture.

Stewart and Simonyi reportedly split in 2008

After 15 years of friendship and relationship rumors, Stewart and Simonyi reportedly split for good in February 2008. Stewart claimed in the Netflix documentary Martha that her post-prison life was “less exciting” — and that was what led to the demise of their relationship.

In August 2008, just six months after the two called it quits, Simonyi became engaged to Lisa Persdotter, the daughter of a Swedish millionaire, the Huffington Post reported. In Martha, Stewart opened up about learning that Simonyi was engaged.

“He said, ‘You know, Martha, I’m going to get married ... to Lisa,’ ” Stewart recalled in the Netflix doc. “I said, ‘Lisa who?’ He hadn’t told me a word.”

She continued, “I thought that was the most horrible thing a person could do. How can a man who spent 15 years with me do that? What a stupid thing to do to someone that you actually care about.”

Simonyi and Persdotter wed in Sweden in November 2008. The couple have two daughters together: Lillian, born in February 2011, and Livia, born November 2012.