In 1809 Saxe-Weimar and Saxe-Eisenach , which had been united only in the person of the duke , were formally merged into the Duchy of Saxe-Weimar-Eisenach .
In 1809 Saxe-Weimar and Saxe-Eisenach , which had been separate duchies with the same duke became one country as the Duchy of Saxe-Weimar-Eisenach .