When John Ernest died childless as well in 1638 , the line of the Dukes of Saxe - Coburg - Eisenach ended .
The country was divided between Saxe - Weimar and Saxe - Altenburg , the other two Ernestine duchies existing at that time .
When John Ernest died childless as well in 1638 , the line of the Dukes of Saxe - Coburg - Eisenach ended and the country was divided between Saxe - Weimar and Saxe - Altenburg , the other two Ernestine duchies existing at that time .