Sachsenhain

Sachsenhain, is the name of a monument created in Adolf Hitler's Third Reich in memory of the Verden massacre, in which 4,500 Saxons are said to have been murdered by Charlemagne's troops. This would have been a reprisal for an earlier Saxon uprising.

The key point is that the Saxons were forced by the Franks under Charlemagne to convert to non-Germanic Christianity and give up their old Germanic religion, and that those who refused to do so were oppressed, persecuted and even murdered. The Verden massacre is an example of the latter. The Nazis saw a parallel between this fact and the Treaty of Versailles, in which France and the other Allies had imposed heavy peace payments on Germany after World War I.

Wikipedia