Flag of Germany
While the use of black-red-gold had been suggested in the Soviet zone in 1946, the Second People's Congress in 1948 decided to adopt the old black-white-red tricolour as a national flag for East Germany. This choice was based on the use of these colours by the National Committee for a Free Germany, a German anti-Nazi organisation that operated in the Soviet Union in the last two years of the war. In 1949, following a suggestion from Friedrich Ebert, Jr., the black-red-gold tricolour was instead selected as the flag of the German Democratic Republic upon the formation of this state on 7 October 1949. From 1949 to 1959, the flags of both West and East Germany were identical. On 1 October 1959, the East German government changed its flag with the addition of its coat of arms. In West Germany, these changes were seen as a deliberate attempt to divide the two Germanys. Displaying this flag in West Germany and West Berlin—where it became known as the (divider-flag)—was seen as a breach of the constitution and subsequently banned until the late 1960s.
Tricolour (flag)
The flag of Germany (black-red-gold) originated as the flag of the revolutionary, anti-monarchist Freikorps of the 1830s and was later adopted by the republicanist bourgeoisie, at the time known as "Dreifarb", a German calque of "Tricolore". This flag was a symbol of opposition against the German "Kleinstaaterei" and the desire for German Unification. It was at first illegal in the German Confederation, but was adopted as the national flag at the Frankfurt Parliament of 1848/9. The flag of Belgium was introduced in a similar context, in 1831, its colours taken from the flag used in the Brabant Revolution of 1789.
The first national flag of the New World inspired by this symbolism was the flag of Mexico, adopted when the First Mexican Empire gained independence from Spain in 1821.