Saxe-Coburg (German: Sachsen-Coburg) was a duchy held by the Ernestine branch of the Wettin dynasty in today's Bavaria, Germany.

Because the Districts of the Coburger Land were assigned to Duke John Ernest as “equipment” (Ausstattung), they remained unaffected by the measures against the outlawed Electors.

But he failed in his efforts to regain the rank of the Elector for himself and his House, fell into conflict with the Emperor (Grumbachsche Händel, or “Grumbach Feud”), and was eventually outlawed and imprisoned until his death.

With the Erfurter Division Treaty of 1572 the remaining lands were eventually and forcibly divided between the sons of the defeated John Frederick II.

Above all, he established as the nucleus of Coburger government an administrative apparatus that would survive for a long time after his death and through many wars and political upheavals.

Three quarters of the Altenburger area, including the Coburger Land, were secured, with the Gotha Division Treaty (Gothaer Teilungsvertrag) of 1672, for the new sovereign, Ernest I “the Pious”, of Saxe-Gotha, who died in 1675.

Because the trial of the common administration of the territories failed at the Schloss Friedenstein in Gotha, the inheritance had to be distributed on 24 February 1680 among the seven brothers.

The reconstruction of the Schloss Ehrenburg, burned in 1690, in the Baroque style eventually led to the ruin of the finances of the Principality, which could not be prevented by the minting of inferior coins.

Between Bernhard I of Saxe-Meiningen and his youngest brother John Ernest IV of Saxe-Saalfeld, strife lasted for thirty-five years, ending only in 1735 with several interventions from the Holy Roman Emperor, Charles VI, in Vienna.

Saxe-Meiningen received the District of Neuhaus am Rennweg and the jurisdiction of Sonneberg while Saxe-Saalfeld was united with the remaining territories of Saxe-Coburg to become Saxe-Coburg-Saalfeld.

Christian Ernest remained in Saalfeld while Francis Josias chose Coburg as his residence and his decision would stand until the end of the monarchy in 1918.

In 1747, he was able to anchor his birthright (primogeniture) in the Line of Succession Laws and confer it on his rapidly growing family for the long-term survival of the House of Saxe-Coburg-Saalfeld.