Flag of Germany
When Heinrich XI, Prince Reuss of Greiz was appointed by Joseph II, Holy Roman Emperor to rule the then-new Principality of Reuss-Greiz on 12 May 1778, the flag adopted by the "Fürstentum Reuß-Greiz" was the first-ever appearance of the black-red-gold tricolour in its modern arrangement in any sovereign state within what today comprises Germany – the Reuss elder line that ruled the principality used a flag whose proportions were close to a "nearly square"-shape 4:5 hoist/fly ratio, instead of the modern German flag's 3:5 figure.
National colours of Germany
The colours ultimately hark back to the tricolour adopted by the "Urburschenschaft" of Jena in 1815, representing an early phase in the development of German nationalism and the idea of a unified German state. Since the 1860s, there has been a competing tradition of national colours as black, white, and red, based on the Hanseatic flags, used as the flag of the North German Confederation and the German Empire. The Weimar Republic in 1919 opted to re-introduce the black, red, and gold tricolour. This was controversial, and as a compromise, the old flag was reintroduced in 1922 to represent German diplomatic missions abroad. As a reaction, "Reichsbanner Schwarz-Rot-Gold" was an organization formed in 1924 representing the parties supporting parliamentary democracy, and for the remainder of the existence of the Weimar Republic, black-red-gold represented the centrist parties supporting parliamentary and black-white-red represented its nationalist and monarchist opposition.