Nathansen grew up in a merchant family in
Copenhagen. Abandoning a legal career, he turned to writing and later directing. His best known work,
Indenfor Murene, premiered in 1912 at the
Royal Danish Theatre, directed by the author. The play centers around a wealthy, loving, but conservative Jewish family whose only daughter breaks away from tradition by attending lectures at the university and secretly becoming engaged to her teacher, a
gentile. Still frequently performed, the play was included in the official
Canon of Danish Culture in 2006. Nathansen's 1932 novel
Mendel Philipsen & Søn, about a Jewish woman who falls in love with a gentile painter but instead enters into a loveless marriage with her Jewish cousin, was adapted for the 1992 movie
Sofie. Late in his career, Nathansen wrote a number of biographies, notably one of
Georg Brandes (1929). In October 1943, when the Nazis attempted to round up the Danish Jews, Nathansen
fled to Sweden. Four months later, he killed himself. ==Legacy==