As a prisoner of war he was brought to the United States where he had to work on the field and in the woods, in his free time he began with drawing.

After the war, he worked as a decorator for Polydor, designed movie posters for local cinemas and started his own advertising agency.

Rösler moved from Stuttgart to Cologne in 1960 where he became head of the set design department for the record label Electrola.

As part of this job he was in charge of the stage arrangements for a Maria Callas Tournee, the Ansbach Bach Week, the Bayreuth Festival and the German Schlager-Festival in Baden-Baden.

During his time in Cologne, Rösler met Wolf Vostell who was also working for the Electrola as a cover art designer.

After his recovery he worked as a freelancing graphic designer, caricaturist, exhibition architect and was responsible for the pagination of the German Physicians Journal.

This is how the Gruppe 91 was founded, it is named after city-district number to that time of Ostheim (part of Kalk, Cologne) where the community lived.

On an area of about 5000 m2 at the Friedrichshafen Fair 1981 his work became accessible to a wider audience in the exhibition called ... für eine neue Welt ... (... for a new world ...).

Since his passing in 2006, members of the Gruppe 91 still live by Rösler's spirit and carry on his artistic legacy in the G91-Bau and further local exhibitions.