Rembrandt’s 1661 double portrait “Two African Men” is a rare depiction of free Black men in 17th-century Amsterdam and a particularly prized work in the collection of the Mauritshuis, a jewel-box museum of Golden Age masterpieces in The Hague.

The art historian Abraham Bredius, the museum’s former director, bequeathed the painting to the Mauritshuis upon his death in 1946, along with two dozen other paintings by Rembrandt and other painters.

But Bredius’s heirs are demanding the return of all 25 of those paintings, saying that the Mauritshuis has not complied with a condition of the bequest, which stipulates that all of the artworks must always be on permanent display. Only a fraction are currently on view.

On Thursday, lawyers for the heirs filed a motion in The Hague’s district court, calling the museum’s behavior a “gross violation” of the terms of the bequest. They are demanding an annulment and the immediate release of the artworks to their family.

“Bredius was very clear what he wanted,” Otto Kronig, one of the claimants, said in an interview. “It’s a slap in the face of Abraham Bredius. If he had known this, he wouldn’t have done that bequest.”