As the number of athletes kneeling for the national anthem across the sports world increases, Anthony Ervin is a particularly intriguing one to have brought swimming squarely into the debate.

Colin Kaepernick first sat for the anthem during NFL preseason games in early August of 2016, but after speaking with former NFL long-snapper and US Army Green Beret Nate Boyer, switched to kneeling. He first knelt in a regular-season game on August 28th, 2016, then met with the media and cited as his motive ongoing issues regarding police brutality and the oppression of people of color in the United States. He continued to kneel through the 2016-2017 NFL season, with a few other athletes following suit.

Though Kaepernick opted out of his contract with the 49ers in March and was never re-signed (in fact, he filed a collusion report against every NFL team today), his movement regained momentum in September when President Trump suggested that players who protest during anthem are un-American and should be fired. Since those comments, athletes from a number of professional sports have decided to kneel.

The action has turned into a national debate over the athletes’ right to peacefully protest, with critics saying that the action is disrespectful to members of the military.

Ervin knelt at Sunday’s 2017 Raia Rapida meet in Brazil, where he anchored Team USA’s mixed 200 medley relay.

Anthony, 36, is the son of Jack Ervin, an American, black Vietnam veteran who opted to join the Marines instead of do jail time after he was wrongly implicated in an act of vandalism, according to Ervin’s autobiography Chasing Water. His mother, Sherry, is of Jewish heritage and is white.

Additionally, his mixed-race ancestor Shadrach Battles fought in numerous Revolutionary War battles, and his great-great-great grandfather William Slaughter fought for the Union in the Civil War.

Ervin was the first black American swimmer to win swimming gold with the 50 free in 2000. Reflecting on his win in Sydney, Ervin told his autobiography co-author Constantine Markides, “I didn’t know a thing about what it was like to be part of the black experience … But now I do. It’s like winning gold and having a bunch of old white people ask you what it’s like to be black. That’s my black experience.”

His demonstration comes about three weeks after Oakland Athletics catcher Bruce Maxwell became the first MLB player to kneel. Notably, Maxwell was born in Germany while his father was stationed there with the Army.

Ervin has historically been outspoken in regard to political and social causes, once going as far as to auction off his gold medal on eBay for the benefit of the Tsunami Relief Fund after the 2004 Indian Ocean earthquake and tsunami. More recently, he made his stance known after the “Unite the Right” march in Charlottesville in August:

The nazis will be America's ancient enemy 3,000 years from now. And even then we'll still beat them if we have to. — Anthony Ervin (@AnthonyErvin) August 15, 2017

As of publishing, Ervin hasn’t made a statement regarding his decision to kneel.