Since their inception, under the reign of the Duchess Jeanne (1356–1406, the last of the House of Louvain) and the ‘Joyous Entrance” of Philip the Fair (1494–1506, the elder son of the Emperor Maximilian and father of Charles V), the Assemblies of the Estates of the Country and Duchy of Brabant (die Staeten van Brabant), which were modeled after the French, exercized their mandate through the princes, first of a junior branch, then later the elder branch of the House of Burgundy–Valois, e.g., Antoine of Burgundy (1406–15), Jean IV (1415–27), Philippe de Saint-Pol (1427–30), Philip the Good (1430–67), Charles the Bold (1427–77), Marie of Burgundy (1477–82) and Maximilian of Austria (first as husband of Marie, then as tutor and Regent until the majority of Philip the Fair). The protocols, derived from the practices of the preceding century and a half, were observed without major alteration up until the demise of the Ancien Régime.

From beginning to end, the Assemblies of Brabant were made up of representative from three groups: the Prelates (die prelaeteri), the Barons and the Knights (die baenrodsen ende ridderen), and the cities and the townships (die steden ende vriheden). They were frequently convened by summons of the Prince – such was the practice – or else gave advice under their own initiative in exceptional circumstances. However, few who were summoned responded to the call; there were many more members called than representatives deputized to appear.