VIENNA — Last Monday in the imposing Ephrussi Palace, Edmund de Waal presided over a family reunion. For the first time since World War II, 41 relatives from around Europe, the United States and Mexico toured the neo-Renaissance building that had been home to the Ephrussi family, European Jews whose wealth once rivaled that of the Rothschilds.

“Itʼs not just a nice family gathering — itʼs a political act,” said Mr. de Waal in an interview the next day. Mr. De Waal, a British ceramic artist and best-selling author, is the great-grandson of Viktor von Ephrussi, who thrived in Vienna as a banker before fleeing the city after Hitler’s 1938 incorporation of Austria into the Third Reich. On Tuesday, the country’s president, Alexander Van der Bellen, welcomed the family to an exhibition opening nearby that tells their story.

“The Ephrussis: Travel in Time,” at the Jewish Museum Vienna through March 8, presents the family’s history through documents, photographs and souvenirs that Mr. de Waal donated to the museum last year. But the stars of the show are 157 netsuke (pronounced NET-ske), tiny Japanese carvings in wood and ivory, made famous by Mr. de Waal’s 2010 memoir, “The Hare With Amber Eyes.” The book, which takes its name from one of the figures, tells the story of the collection and the family, which survived World War II by spreading out into a worldwide diaspora.