Complex sentence: In 1810 he was appointed professor extraordinarius of German literature at the University of Berlin in the following year he was transferred in a similar capacity to the University of Breslau, and in 1821 returned to Berlin as professor ordinarius.
Split into simpler sentences: In 1810 he was appointed professor extraordinarius of German literature at the University of Berlin. In the following year he was transferred in a similar capacity to the University of Breslau, and in 1821 returned to Berlin as professor ordinarius.