The Thringer Schiefergebirge, a region spanning the German federal states of Bavaria, Saxony and Thuringia and north-western Bohemia in the Czech Republic, which was split into three areas, Weida, Greiz and Gera-Plauen in 1209, was part of the Holy Roman Empire under King Conrad III in the 12th century.
The Thuringian Highland, Thuringian Highlands or Thuringian-Vogtlandian Slate Mountains (German: Thuringer Schiefergebirge or Thuringisches Schiefergebirge, literally "Thuringian Slate Hills") is a low range of mountains in the German state of Thuringia. 
