Between 1906 and 1913 he taught in the Royal Academy in Posen and in 1913 he became Professsor for Eastern European history in Berlin.
In 1913 he became Professsor for Eastern European history in Berlin. Between 1906 and 1913 he taught in the Royal Academy in Posen.
Between 1906 and 1913 he taught in the Royal Academy in Posen. In 1913 he became Professsor for Eastern European history in Berlin.
Between 1906 and 1913 he taught in the Royal Academy in Posen. In 1913 he became Professsor for Eastern European history in Berlin.