Evening Twilight, Moonrise (Sylt), 1910
Oilpainting on wood by Franz Korwan

Korwan once phrased his artistic perspective this way:  "For me, the motif is never to be found in objective things, but mostly in the air or in the allure of colors, primarily and almost exclusively the way they appear at the North Sea. Nothing shows the logical consistency of nature's laws more than the sea. One can paint it only when one has understood the inner connections, just as a doctor must thoroughly know and master the anatomy of the body."
  
The year 1920 marked a turning point in the life of Franz Korwan alias Sally Katzenstein.  He withdrew from public life for private and personal reasons.  But in the 1930s his voluntary withdrawal became an imposed isolation. With Hitler's takeover in 1933, a dreadful life began for Korwan. All the accomplishments he had achieved for the island were forgotten. Suddenly only his parentage still mattered.
With the start of the Nazi regime Korwan and his life partner were increasingly shunned. After the National Socialists had first expelled the Jewish spa guests, the attacks were soon directed against the few Jews residing on Sylt. In 1937 Franz Korwan, with his life partner Else Saenger, left the island in order to be able to withdraw into the masses of a large town.  However, neither in Wiesbaden nor in Baden-Baden could they find the hoped-for protection.  In 1940 both were arrested in Baden-Baden and deported.  The National Socialists turned Franz Korwan back into Sally Katzenstein.
His last exhibit on the island took place in 1934.  Six decades later, in April/May 1993, after many previously futile efforts, the Keitum Heimatmuseum [local museum] mounted another exhibit of paintings by Franz Korwan, which was realized thanks to the dogged research over many years by the teacher Joachim Pleines and the president of the Sylt Friends of Art, Elke Harms. In the context of the exhibit opening, Korwan researcher Pleines said: "In answer to the hypothetical question as to whether Korwan would have survived here (on Sylt), it must not be forgotten that three of the local assimilated Jews were condemned to imprisonment in concentration camps, from which two did not return. If we view Korwan only as a painter, we would not do justice to his person and we would have had a hand, 60 years after the [Nazi] takeover, in suppressing a painful part of the history of Sylt."