Flag of Belgium
|Design||A vertical tricolour of black, yellow, and red. |
After the death of Charlemagne, the present-day territory of Belgium (except the County of Flanders) became part of Lotharingia, which had a flag of two horizontal red stripes separated by a white stripe. The territory then passed into Spanish hands, and after the coronation of Charles V, Holy Roman Emperor yellow and red, the colours of Spain, were added. From the 16th century to the end of the 18th century, the colours of what is now Belgium were red, white and yellow. Occasionally the red cross of Burgundy was placed on the white section of the flag.
During the period of Austrian rule, a number of different flags were tried, until the Austrian Emperor imposed the Austrian flag. The population of Brussels was opposed to this, and following the example of France, red, yellow and black cockades began to appear; those being the colours of Brabant. The colours thus correspond to the red lion of Hainaut, Limburg and Luxembourg, the yellow lion of Brabant, and the black lion of Flanders and Namur.
On August 26, 1830, the day after the rioting at the Brussels Opera and the start of the Belgian Revolution, the flag of France flew from the city hall of Brussels. The insurgents hastily replaced it with a tricolour of red, yellow and black horizontal stripes (similar to the one used during the Brabant Revolution of 1789-1790 which had established the United States of Belgium) made at a nearby fabric store. As a result, Article 193 of the Constitution of Belgium describes the colours of the Belgian nation as Red, Yellow and Black instead of using the order shown in the official flag.
On January 23, 1831, the stripes changed from horizontal to vertical and October 12 saw the flag attain its modern form, with the black placed at the hoist side of the flag. It is suggested that the change occurred to more clearly distinguish the flag of Belgium from the Dutch flag (which also has three horizontal stripes) - especially important during naval battles. 
The vertical design was based on the flag of France. The colors are those of the arms of the duchy of Brabant (yellow lion with red claws and tongue on a black field).