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.
Flag of Germany
In 1955, the inhabitants of the French-administered Saar Protectorate voted to join West Germany. Since its establishment as a separate French protectorate in 1947, the Saar had a white Nordic cross on a blue and red background as its flag. To demonstrate the commitment of the Saar to be a part of West Germany, a new flag was selected on 9 July 1956: the black-red-gold tricolour defaced with the new coat of arms, also proposed on this day. This flag came into force on 1 January 1957, upon the establishment of the Saarland as a state of West Germany.