The Belgian flag is tri-colored with equal horizontal bands. The colors are based on the former duchy of Brabant. This flag represents a Lion of Gold, a black background and a tongue and throat in red. Today in the Belgian Tri Color we see a black left site representing the background. Yellow is the middle color representing the Brabant Lion and red is representing the throat and the tongue.
On August 26, 1830, the day after the rioting at the Brussels Opera, and the start of the Belgian Revolution the flag of France was flown from the city hall of Brussels. This was hastily replaced by a tricolour of red, yellow and black horizontal stripes made at a nearby fabric store, similar to the one used during the Brabantian Revolution.As a result, article 193 of the Constitution of Belgium describes the colours of the Belgian Nation as Red, Yellow and Black instead of the order used in the above official flag.
On January 23, 1831, the stripes were 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 was to more clearly distinguish the flag of Belgium from the flag of the Netherlands, which also has three horizontal stripes, especially important during naval battles. Some think the change to vertical was a gesture of sympathy with the French, again clearly separating them from the Dutch.