Throughout his tenure, public discussions on the integration of Germany's largely Muslim immigrant population featured prominently. In 2011 he published "Mut zur Integration – für ein neues Miteinander" ("Courage for integration - for a new together"), a book written in response to the controversial book "Germany Abolishes Itself" written by his former State Minister of Finance Thilo Sarrazin. That same year, he appointed Turkish-origin politician Dilek Kolat Senator for Labour, Integration and Women. In May 2012, Wowereit named Şermin Langhoff artistic director of the Maxim Gorki Theater.