The younger son of Jewish antiques dealer Alexandre Rosenberg, Paul and his elder brother Léonce joined their father's business.

During the tour, Paul bought two van Gogh drawings and a Manet portrait for $220, which he had transported to his father's gallery and sold onwards at a profit.

[1][3] Paul's stock included pieces by all of the classical and contemporary French and major European artists, and latterly American artists, including: Marsden Hartley; Max Weber; Abraham Rattner; Karl Knaths; Harvey Weiss; Oronzio Maldarelli; Nicolas de Staël; Graham Sutherland; Kenneth Armitage; and Giacomo Manzù.

Rosenberg lent Picasso money after his honeymoon with the ballerina Olga Khokhlova and found them an apartment in Paris next to his own family home, generosity which resulted in a lifelong friendship between these two very different men.

[5] By 1935 along his brother-in-law Jacques Helft, a noted antiques dealer, he opened a branch in Bond Street, London, to enable them to engage with more Americans.

[3] All looted art works, including Paul Rosenberg's, were initially shipped by truck to the depot created in the Galerie nationale du Jeu de Paume.

[3][8] Rosenberg, his wife, his daughter Micheline and her husband Joseph Robert Schwartz,[2] all travelled via Lisbon, arriving at the Madison Hotel in New York in September 1940.

[9] From this base post-war, Rosenberg managed to reclaim and re-purchase a number of pieces from his pre-war collection, but these represented less than half of the works he had lost.

[3][10] These included Nude Reclining by the Sea (1868) by Gustave Courbet, which was taken on 5 September 1941 by the ERR in a raid on Rosenberg's bank vault in Bordeaux together with another 162 of his paintings.

Following Joseph Goebbels personal directive to sell these degenerate works for foreign currency to fund the building of the Führermuseum and the wider war effort, Hermann Göring appointed a series of ERR-approved dealers to liquidate these assets.

[5] In December 1987, while reading at the Frick Museum in New York, Elaine Rosenberg found the painting Portrait of Gabrielle Diot by Degas listed for sale in an art magazine at the Mathias F. Hans Gallery in Hamburg.

[23][24] In 2012, the Rosenberg family identified Profil bleu devant la cheminée (Woman in Blue in Front of Fireplace; 1937), a Matisse painting that was confiscated by the Nazis in 1941,[25] in an exhibition catalogue and demanded that the Henie-Onstad Art Centre (HOK) near Oslo, Norway, return it.

Rosenberg had bought the painting directly from Matisse in 1937 and had it stored at the time of the Nazi invasion in a bank vault in Libourne, a commune in the Gironde in Aquitaine, southwestern France.

The ERR entered the vault in March 1941, and, after cataloging at the Galerie nationale du Jeu de Paume in September 1941, it was earmarked for Göring's private collection.

Although under Norwegian law, due to the period of ownership, the painting now belongs to HOK, Norway was one of 44 signatories to the 1998 Washington Conference Principles on Nazi-Confiscated Art.

Protracted mediation, overseen by Christopher A. Marinello of the Art Recovery Group, saw the painting returned to the heirs of Paul Rosenberg in March 2014.

[26] In May 2015, Marinello also recovered, for the Rosenberg heirs, Portrait of a Seated Woman by Henri Matisse, which had been found in the Munich home of Cornelius Gurlitt.