Flag of Germany
With the formation of the short-lived Weimar Republic after World War I, the tricolour was adopted as the national flag of Germany. Sixteen years later following World War II, the tricolour was again designated as the flag of both West and East Germany divided states in 1949. The two flags were identical until 1959, when the East German flag was augmented with the coat of arms of East Germany. Since reunification on 3 October 1990, the black-red-gold tricolour has become the flag of a reunified Federal Republic of Germany.
Reichskriegsflagge
Because Prussia had emerged as the leading German state and the black-red-golden colour scheme was, at that time, associated with pan-Germanism (a Germany including Austria) and the revolution of 1848, the Prussian King and President of the North German Confederation, Wilhelm I, insisted on using new flags inspired by Prussia and without the traditional German colours. Therefore, the North German and eventually Imperial German flags prominently featured the Prussian colours (black and white) as well as symbols like the Prussian eagle and the Iron Cross. And while seafaring was the traditional domain of the Hanse in Germany, virtually all of the 19th century German coastline (including the North Sea coast) and naval power belonged to Prussia after the decisive victory in 1866.