Flag of Brussels-Capital Region
|Design||A stylised iris upon a blue field. |
The first flag was adopted by the Capital Region in 1991. A new flag based on the city's current logo became official in early 2015. 
The yellow iris, an Iris pseudacorus, as a symbol for Brussels dates back to before 1924 with Cornette writing that the flower was chosen to represent the city as it could be found growing in the marshes – the city itself was founded on marshy ground on Saint-Géry Island – today even through the expansion and industrialisation of the city.
The plant used to surround the city walls and, according to legend, gave a key victory to the Dukes of Brabant: knowing the plant could only grow in shallow water, the Duke's troops could gallop through the flooded plains by keeping to the iris covered areas. His opponents however, seeing them crossing but not knowing of the iris, attempted to cross but got bogged down in the marshes.
The flower also featured on the sceptre of the descendants of Charlemagne. This included Charles of France, who set up a fortified camp in the area, in the Duchy of Lower Lotharingia, and chose the site as the capital. This is considered the foundation of Brussels.