Conversation so far:
what did Alfred Rosenberg do with the nazis?
In 1923, after the failed Beer Hall Putsch, Adolf Hitler, who had been imprisoned for treason, appointed Alfred Rosenberg as the leader of the National Socialist movement until Hitler's release.
what did Alfred Rosenberg do as leader of the National Socialist movement?
In 1929 Alfred Rosenberg founded the Militant League for German Culture.

Question: what did the militant league do?
Self-contained rewrite: What did the Militant League for German Culture do?