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.
Lützow Free Corps
Throughout the 19th century, these anti-Napoleonic Free Corps were greatly praised and glorified by German nationalists, and a heroic myth built up around their exploits. Inasmuch as many Lützow Free Corps veterans took part in the first Wartburg festival of 1817, demanding German unity and democratic reforms, the black-red-gold color scheme formed by the combination of black cloth, red trim, and brass buttons on their uniforms would later become associated with republican and nationalist (or Pan-German) ideals. During the Hambacher Fest of 1832 and Revolutions of 1848 in the German states, flags with these colors were used, if even often displayed in reverse order compared to modern day's flag of Germany. This combination, reminiscent of the Holy Roman Empire of the German Nation (whose heraldic coat-of-arms depicted a black eagle on a shield of gold, often in later times with red beak and legs), was selected as the official national colors of the German flag in 1919, and again in 1949.