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
Upon the Nazi Party's "Machtergreifung" when Adolf Hitler came to power in January 1933, the "democratic" colours quickly fell out of use, though they were not officially abolished. By order of March 7, two days after the German federal election, Reich President Paul von Hindenburg re-introduced black, white, and red as official decorations on the coming "Volkstrauertag" public holiday. Alongside the swastika flag of the Nazi Party, the imperial colours were restored as a provisional national symbol, subject to a final decision by the German government. The concurrent Nazi flag also used a combination of black, white, and red colours, but not in the same way as the old flag of the German Empire. Instead, the socialist red was the dominant colour.