Who Is Wladimir Klitschko? 7 Things to Know About Hayden Panettiere's Ex-Fiancé

Hayden Panettiere welcomed her only child, daughter Kaya Evdokia Klitschko, with her ex-fiancé, Wladimir Klitschko.

The pair dated on and off from 2009 until their final split in 2018. Over the course of their nearly decade-long romance, they became engaged and started a family together.

Following Hayden's death, here's everything to know about Wladimir and their past relationship.

Born on March 25, 1976, Wladimir followed in his older brother Vitali Klitschko's footsteps in the boxing world. The Hall of Fame heavyweight champion notably won gold when he represented Ukraine at the 1996 Summer Olympics in Atlanta, Ga., before turning professional.

Throughout his career Wladimir held the WBA, IBF, WBO and IBO heavyweight titles. He announced his retirement from professional boxing in August 2017, with a record of 64 wins in 69 fights and more than 50 knockouts.

Outside the boxing ring, Wladimir has been a longtime activist for Ukraine for years.

Hayden joined Wladimir and his brother, Vitali Klitschko, onstage during the Maidan protests in Kyiv in December 2013, where she voiced her support for demonstrators calling for democratic reforms.

Despite their split, Hayden continued to stand behind Wladimir's efforts following Russia's full-scale invasion of Ukraine in 2022. Early in the war, the former child star urged Americans to donate to Hoplon International amid the "gut-wrenching" suffering of Ukrainian civilians.

"I can't continue to sit on the sidelines watching as this disaster rages on," she said.

Wladimir and Hayden first crossed paths at a mutual friend's party in 2008.

While she was in a relationship at the time, she reportedly made the first move and told him, "You're huge." The former professional boxer reportedly replied, "You're tiny."

Neither Wladimir nor Hayden disclosed exactly when they began dating, but they briefly split in May 2011 after about two years together.

"Even though we've decided splitting up is best for both of us, we have an amazing amount of love and respect for each other and remain very close friends," Hayden said at the time.

Meanwhile, Wladimir shared, "We had a great time together, but it's not that easy to manage a relationship between two continents. I have a lot of respect for Hayden as a person and as a friend, and I believe we'll keep our friendship even after the separation."

The two reconciled and eventually confirmed their engagement in October 2013.

In May 2014, a source told Us Weekly the Nashville actress and her then-fiancé were expecting their first child together. They welcomed Kaya on December 9, 2014.

"He is just so over the moon," she said of Wladimir in an interview with People at the time. "I'm lucky if I can get my hands on the kid. He's like, 'No, no, I got her.' Which is exactly what I thought he would be like."

In an August 2018 interview with RadarOnline.com, Lesley Vogel confirmed the Heroes actress had called off her engagement to Wladimir. Hayden was spotted holding hands with Brian Hickerson at a Los Angeles restaurant at the time.

"She needs to take a little bit of a break and make some decisions on her own of what she wants to do. So I think she is in a very good place," she continued.

A few months after their split, Hayden relinquished full custody of Kaya to Wladimir, which she said was "incredibly difficult."

"The fact that my child wasn't going to be with me all day, every day was...you can't put words to it. It's just a really intense feeling or multiple feelings really layered together," she shared on Jay Shetty's podcast "On Purpose."

Wladimir and Kaya then relocated to Ukraine after Hayden decided that her daughter would live with her father amid her struggles with addiction. The former couple appeared to be on good terms in the years leading to Hayden's death.