Saxe-Coburg and Gotha (German: "Sachsen-Coburg und Gotha" ), or Saxe-Coburg-Gotha, was an Ernestine duchy ruled by a branch of the House of Wettin, consisting of territories in the present-day states of Bavaria and Thuringia in Germany. It lasted from 1826 to 1918.
Can we infer the following?
This duchy ended around the end of world war 1
Yes