Naomi Watts and Liev Schreiber have called it quits after 11 years together.
The two-time Australian Oscar nominee and the San Francisco-born Tony Award-winning actor, best known for his starring role in the crime-drama TV series Ray Donovan, announced on Monday they had ended their relationship.
The Hollywood power couple, who have sons Sasha, 9, and Samuel, 7, never married, regularly saying in interviews they did not need a certificate to prove their love and commitment to each other.
"Over the past few months we've come to the conclusion that the best way forward for us as a family is to separate as a couple," Watts and Schreiber said in a joint statement.
"It is with great love, respect and friendship in our hearts that we look forward to raising our children together and exploring this new phase of our relationship.
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"While we appreciate your curiosity and support, we ask the press to be mindful of our children and respect their right to privacy."
The united front is in contrast to the recent break-up of another Hollywood power couple, Angelina Jolie and Brad Pitt.
Jolie filed for divorce, sparking what could be a contentious, highly-public battle for custody of their six children.
Watts, who had her start on Australian TV shows including Home and Away and Hey Dad!, became one of the industry's most respected actresses after first struggling in Hollywood and living in the shadow of close friend Nicole Kidman.
Watts, who turns 48 on Wednesday, finally broke through in David Lynch's 2001 thriller Mulholland Drive and went on to score Oscar nominations for 2003's 21 Grams and 2012's tsunami survival drama The Impossible.
Schreiber, 48, won his Tony Award in 2005 for Glengarry Glen Ross and earlier this year shared a Screen Actors Guild Award for best ensemble as part of the cast of Spotlight.
The couple and their children lived a jet-set live, with homes in Los Angeles and New York and the family travelling together to movie sets around the globe.
"We are like circus people," Schreiber told AAP in 2009.
"We don't know anything else.
"It may seem irresponsible to some people but not to us.
"There was a level of pride that Sasha had been to eight countries by the time he was six months old."
In 2014, while promoting the comedy-drama While We're Young, Watts spoke about how in her 40s she had become re-energised about her career.
"You feel, 'I've reached the mid-life point. What else haven't I done? What else do I need to squeeze in?'" she said.
"And that fear of, 'Is it going to go away?'
"In my 20s I was all about having fun."
