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.
Reichskriegsflagge
Prince Adalbert of Prussia, the commander-in-chief of the North German Navy, was commissioned with finding the design of the new war ensign. Around 1850, he already had designed a number of potential war ensigns for a hypothetical German nation-state under Prussian rule, which never were adopted as the project was not realized at that time. He used his old ideas to design the new North German war ensign with heavy involvement of the Prussian King, leading to numerous changes, like the inclusion of the Iron Cross in its original shape.