 More than 1,500 places were ordered to be renamed by 16 July 1938 following a decree issued by Gauleiter and Oberpräsident Erich Koch and initiated by Adolf Hitler.Many who would not cooperate with the rulers of Nazi Germany were sent to concentration camps and held prisoner there until their death or liberation.After the 1939 invasion of Poland by Nazi Germany opening World War II, the borders of East Prussia were revised.