Heirs of Piet Mondrian, who cofounded the De Stijl movement and coined the term neoplasticism, are suing the Philadelphia Museum of Art (PMA) for the return of a 1926 painting by the Dutch artist that they claim was looted by Nazis in 1937. Valued at more than $100,000, Composition with Blue entered the museum’s collection in 1952, after it was bequeathed to the institution by A. E. Gallatin. The collector had purchased it in 1939 from New York’s Buchholz Gallery, a known purveyor of Nazi-seized art. The gallery is alleged to have obtained it following its 1938 seizure from Germany’s Hanover Museum as “degenerate” art.The news was first reported in the Philadelphia Inquirer, which noted that the legal proceedings began last week and are being undertaken on behalf of the descendants of Mondrian’s sole immediate heir, Harry Holtzman. For its part, the museum has said it will “vigorously” defend itself against the “meritless claim.” Per the PMA’s website, Mondrian, who in 1938 fled fascist rule in Paris and two years later arrived in New York, counted Gallatin as a friend. Museum president Timothy Rub told the Inquirer that neither Mondrian, who died in 1944, or Holtzman, who died in 1987, had ever raised objections to museum’s purchase and almost continual display of Composition with Blue, with the artist at one point offering to assist in its restoration. “In the subsequent 30-plus years after Holtzman passed away,” Rub noted, “the executors of the estate, the heirs of Mondrian, did not make any claim for the picture. It’s been in plain sight. Holtzman published a picture of it. What’s changed now?”The PMA in a statement affirmed that it “supports restoring artwork looted by the Nazi regime to its rightful owners, and [has] done so in the past.” The museum earlier this year agreed to return to the Czech Republic a Nazi-seized sixteenth-century “pageant shield” once owned by Archduke Franz Ferdinand, whose 1914 assassination sparked World War I.