The First Reich (962-1806) was the Holy Roman Empire, which included modern day Germany, Austria, the Czech lands, Northern Italy, and various other territories.
Already in the Middle Ages it consisted of several almost independent states, often at war with one another. After the Reformation the authority of the Emperor was further weakened. It was often said that it was "neither Holy, nor Roman, nor an Empire."
The Second Reich was Imperial Germany (1871-1918), as unified by Bismarck.
During the Weimar period (1919-33) the official name of Germany was still "Deutsches Reich."
Ilse Koch (1906-1967) Ilse would pick out prisoners with tattoos and have them killed and then she would have the skin where the tattoo was cut off. She was known as the “Bitch of Buchenwald” for her cruelty at the concentration camp Buchenwald.