Below are 2 sets of photograph stamps of Donat and Anton Herrnfeld, actors, playwrights and theater directors in Berlin. The two brothers together are known to have written around 100 plays and were so successful they bought an eight-hundred seat theater –named the Gebrüder-Herrnfeld Theater–by 1906. The title on all stamps is Was sagen Sie zu Leibusch, or What do you say about Leibusch?, no doubt promoting their latest comedy, sometime in the 1910-15 era.

Anton Herrnfeld (1865-1929) was also in several silent movies of the early 1900’s, mostly as a supporting actor, and can be found in the IMDB movie database online.

Donat Herrnfeld (1860-1916) , the older brother, did only one movie we know of and is less well-known, but most of the brothers’ energy went to their plays and theater. It was not a path to fame or great riches; members of the family helped run the theater and filled-in some acting parts. The theater continued as Gebrüder-Herrnfeld for only 15 years, unfortunately. Donat died in 1916 and Anton sold his ownership in 1921.
The Herrnfeld were Jewish, but the plays were for the general public; they were not in Yiddish, although the plays had Yiddish-influenced dialect and Jewish characters. We would see these plays as similar to modern sit-coms with self-deprecating humor about families and their characters, but some groups were not happy. From some online commentary:
In the Jewish population the experience of anti-Semitism led to a critical debate over comedic forms of self-representation. At the turn of the century the theatrical style of the brothers [David] Donat and Anton Herrnfeld was so successful in Berlin that they moved their by then famous Herrnfeld Theater into its own 800-seat auditorium. When Max Mack filmed the Herrnfeld play “Endlich Allein” (Alone At Last) in 1913, the two brothers played the lead roles. The brothers’ brand of comedy was based primarily on stereotyped figures that — like the businessman Simon Dalles, the clever Dovidl Grün, or Moritz the apprentice — were received as self-caricatures taken from everyday Jewish life. Alongside enthusiastic reviews … there were critical voices, such as the Central Association of German Citizens of Jewish Faith…which in its organ Im Deutschen Reich warned of the dissemination of anti-Semitic clichés in 1902.

As late as 1927 a Herrnfeld play was used for the movie Family Day at the Prellstein’s , which was first staged in 1905. Anton Herrnfeld had a part (see picture), two years before his death. Again from online historical commentary:
This story… was described in 1927 by the critic Georg Herzberg as a “successful and by no means discriminatory version of a ‘Herrnfeldiade'”. Herzberg viewed Family Day at the Prellstein’s as a “clean film” set in an urban milieu, “one you can have a few hearty chuckles over and whose viewers, apart from the hopeless antisemites, will find a pleasant diversion from Heidelberg, the Rhine, and operettas.”
But there was always far right pressure with controlled media criticising the plays and movies on an anti-semitic basis. Hitler’s rise to power in 1933 gradually doomed any Jewish linked theater activity; the builidng was heavily damaged during WW2 and demolished in 1953.
References: Information was taken from online sources such as:
https://navigatingravities.de/brothers-herrnfeld-theater/
https://www.filmportal.de/en/topic/jewish-humor-and-anti-semitism
Thanks to Büro Papier und Pappe for stamps and inspiration.