Original sentence: He defined this "motherland" as the areas that belonged to 10th-century Piast Poland in the era of Mieszko I and Boleslaw Krzywousty (Greater Poland, Silesia, Pomerania, Neumark, West Prussia).In 1924 he published his first concept of the "motherland territories" of Poland
Edited sentence: In 1934 he published a first concept of"motherland territories" of Poland(his first ideas about this concept started in 1924)-that is areas that belonged to Piast Poland before expansion of the Prussian state:Wielkopolska,Silesia, Pomerania, Neumark, Royal Prussia