[2] In 1912, the Lederers met Egon Schiele, who spent that year's Christmas with them in Györ, becoming friends with their son Erich, whom he painted and drew several times.

[4] Their relationship with Klimt was very friendly, intimate to the point that Elisabeth Franziska Lederer, born in 1894, was able to affirm during the Nazi period to be the adulterous daughter of the painter and to receive in 1940 a certificate of filiation establishing that she was only "Half-Jewish", while her two brothers, Erich and Fritz, were considered full Jews.

[7][8] The Lederer collection, confiscated in 1938, was stored mainly at Immendorf Castle in Lower Austria, where it would have largely burned in early 1945 under poorly clarified circumstances - which seems to contradict the fact that Isolated paintings resurfaced after the war, which were returned to the heirs.

[9] In 2013, the Lederer heirs initiated a lawsuit to claim restitution of the Beethoven Frieze which had been looted by the Nazis.

[11][12][13][14] In 2018, a Swiss court in Geneva ordered that the Galerie Kornfeld respond to questions asked by the Lederer heirs concerning artworks by Klimt and Schiele.