The Sonntagskreis was founded in the autumn of 1915 by Béla Balázs, Lajos Fülep, Arnold Hauser, György Lukács, and Károly (Karl) Mannheim; in December of that year Balázs noted the success of the group in his diary.
Balázs was a moving force in the Sonntagskreis or Sunday Circle, the intellectual discussion group which he founded in the autumn of 1915 together with Lajos Fülep, Arnold Hauser, György Lukács and Károly (Karl) Mannheim.