BelgiumFlags / europe, European Union, flags, geography, history, Multi National Organizations, Western Europe On 23 January 1831, the stripes changed from horizontal to vertical, and on 12 October the flag attained its modern form, with the black placed at the hoist side of the flag. Historical flags are shown below: Flag of the Brabant Revolution 1789-1790 Flag of the Belgian Revolution 1830-1831 Pages: 1 2 3 4 5 6