[1] He was one of the earliest supporters in print of Bertolt Brecht, which formed one basis for a long period of very public disagreement - which sometimes degenerating into journalistic feuding - with Alfred Kerr.
His career as a critic began in 1909 when he started to work for "Die Schaubühne" ("The Theatre Stage"), a weekly newspaper owned by Siegfried Jacobsohn.
[6] In 1919 he succeeded Alfred Kerr as the theatre critic on "Der Tag", the mass circulation daily paper produced by August Scherl.
Between 1922 and 1933 at the Berliner Börsen-Courier, under the leadership of Emil Faktor, Ihering built his reputation as one of the most important film and theatre critics in Germany.
His articles targeted the theatre bosses, from whom he demanded consistent multi-faceted and imaginative scheduling, and directors, dramaturges and set designers on whom he urged - both formally and informally - closer and smarter collaboration.
[8] At the end of 1927 Ihering relocated to a newly built three floor storey house in Berlin-Zehlendorf, where he would live out the final fifty years of his life.
[10] In 1945 Ihering took a job as Chief Dramaturge at Berlin's Deutsches Theater, then under the direction of the actor turned theatre director Gustav von Wangenheim.
[12] Between 1955 and 1960 Ihering contributed as a theatre critic to Sonntag (Sunday), the weekly newspaper of the East German Cultural Association.