 Upon his death, Emperor Henry IV assigned it to Henry III, Count of Louvain and Brussels, granting him the Landgrave of Brabant.This is the earliest known use of the term Landgrave.In 1183 the landgraviate of Brabant and the counties of Louvain and Brussels were formally merged and elevated together into the Duchy of Brabant, by Emperor Frederick Barbarossa; Henry I became the first Duke of Brabant.