Original: 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.
Simplified: 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.