This is turning into the Summer of Restitutions with Carol Vogel reporting on a case migrating from Central Europe to the US Courts as heirs of a Hungarian banker seek the return of $100 million in looted art housed in state museums in Hungary:

Now, in what experts say is the world’s largest unresolved Holocaust art claim, the heirs of the Hungarian banker Baron Mor Lipot Herzog have filed a lawsuit in United States District Court in Washington demanding the return of the art collection they say is rightfully theirs. The lawsuit has been filed against Hungary and several museums that it oversees.

The suit, filed on Tuesday, includes an unprecedented twist: in addition to the more than 40 artworks explicitly identified in the filing — including paintings, sculptures and other works by masters like El Greco, Lucas Cranach the Elder, Zurbarán, van Dyck, Velázquez and Monet — lawyers are also asking the Hungarian government for an accounting of all art from the Herzog family in its possession. […] Michael S. Shuster, a lawyer for the Herzog family, said that Hungary had been “one of the countries that has been the most recalcitrant” about returning looted art. “While other countries have cooperated,” he said, “Hungary has been bucking that trend.”

[…] Hungary is not the only country with looted Herzog art. Over the years the family has made legal claims in Poland, Russia and Germany, seeking the return of art and objects seized during and after World War II. This year the German government returned three works: an 18th-century snuffbox said to have belonged to Frederick the Great; a painting by Zeitblom, a 15th-century German artist; and a 1545 portrait by Georg Pencz, which the Herzogs sold at Christie’s in London this month for $8.5 million. That money is being used to support the heirs’ litigation, according to Mr. Shuster

Hungary Sued in Holocaust Claim (New York Times)