[2] The name Saxe-Coburg-Gotha also refers to the family of the ruling House of Saxe-Coburg and Gotha, which played many varied roles in the dynastic and political history of Europe in the 19th and 20th centuries.

In the early part of the 20th century, before the First World War, it was the family of the sovereigns of the United Kingdom, Belgium, Portugal, Bulgaria, and Saxe-Coburg-Gotha.

In 1910, the Portuguese king was deposed, and the same thing occurred in Saxe-Coburg-Gotha in 1918 and in Bulgaria in 1946 (although effective control had already ceased two years prior due to a coup).

As of 2025[update], a branch of the family still reigns in Belgium, and while the British line still technically exists up to the present day, it now uses the name Windsor due to a royal proclamation issued by King George V in 1917.

The Saxe-Meiningen line became Saxe-Hildburghausen and got from Saxe-Coburg-Saalfeld the Saalfelder territories as well as the District of Themar and the places of Mupperg, Mogger, Liebau and Oerlsdorf.

Ernest III, the sovereign of Saxe-Coburg-Saalfeld, had received it in 1816 from the Congress of Vienna for providing assistance to the Allies in their war against France.

But, because of the great distance from Coburg and of the unrest caused by the Hambach Festival, the Duke sold the Principality in 1834 to Prussia.

[5][6] Later attempts to merge the duchies failed in 1867 because the Landtag of Gotha did not want to assume the higher state debts of Coburg and in 1872 because of the questions about the administration of the whole union.

At the Bundesrat in Berlin, where it had a seat, it kept its agents but, since 1913, like most of the other Thuringian states, it had to defer to the Grand Duchy of Saxe-Meiningen for the representation.

Because he had died childless, the throne of the two duchies would have passed to his late brother Prince Albert's male descendants.

Every four years, a common budget, especially in the financial dealings with the German Empire, was made, even if it interfered with the local and national operations of the two Duchies.

They were for trade with Austria-Hungary, Belgium, Argentina, Brazil, Chile, Cuba, Ecuador, France, Great Britain, Italy, Mexico, Peru, Portugal, Prussia, Russia, Spain, Switzerland, and Turkey.

But, on 26 June 1867, because of a treaty signed in 1866 with Prussia, its Army was added, for defending and recruiting purposes, to the 6th Thuringian Infantry Regiment No.

[13] Unlike Prussia, where military service was mandatory, Saxe-Coburg and Gotha filled its quota in the Imperial Army with the draft.

The use of Ducal and Princely titles may be restricted if the marriage conflicts with the requirements of the Staatsgrundgesetz or if a member of the House renounces his claims for himself and his descendants.