The Russian billionaire Roman Abramovich and Garage Magazine founder Dasha Zhukova—one of the contemporary art scene’s biggest power couples—have split. In a statement released to the media on Monday, the couple said: “We are committed to jointly raising our two children. We will also continue to work together as co-founders of the Garage Museum of Contemporary Art in Moscow and the New Holland Island cultural centre in Saint Petersburg.”

Abramovich, the owner of England’s Chelsea Football Club, is ranked 12th on the 2017 Forbes list of Russian billionaires, with a fortune estimated at $9.1 billion. Zhukova, who sits on the boards of the Los Angeles County Museum of Art and the Metropolitan Museum in New York, was ranked 98th on ArtReview magazine’s 2016 Power 100 list of “most influential people in the contemporary art world”. 

Abramovich and Zhukova were together for a decade, but the only indication that they had married came from a 2015 Wall Street Journal Magazine story, and the legal nature of their relationship was not specified in the announcement of their separation. The couple have two children, who were both born in the US. 

They were pictured looking happy late last month at an opening at New Holland, a man-made island in St Petersburg with a history stretching back to Peter the Great. The couple, via Abramovich’s Millhouse, LLC and Zhukova’s Iris Foundation, have been converting it into a public art space.

The Garage Museum is located in a Soviet-era building repurposed by Rem Koolhaas in Moscow’s Gorky Park. The inaugural exhibition in that space in 2015 featured two infinity room installations by Yayoi Kusama. And despite Russia’s increasing isolation, the opening of the Garage Triennial of Russian Contemporary Art earlier this year drew a crowd of international collectors and curators. 

Among the Russian social media speculation on Monday were suggestions that the split was fueled by Western sanctions against Russia. High-level Russian officials have reportedly been divorcing their wives in recent years and by some accounts transferring assets to them as a way to protect their fortunes against potential seizure.