In the Middle Ages they formed a social class with a monopoly on the civil, military and economic leadership of the urban administration, with privileges that survived until the end of the Ancien Régime.

However, tradesmen formed the Nations of Brussels to counter this oligarchical system and in 1421, after violent confrontations, gained some political rights.

The rule of the Seven Houses remained predominant until the end of the Ancien Régime, when these special privileges were definitively abolished, along with those of the Guilds.

Between the 12th and 18th centuries, the magistrates of the Noble Houses of the city of Brussels founded numerous official institutions, including schools, orphanages, pilgrim hostels, infirmaries and almshouses.

As the historian, editor and genealogist François de Cacamp writes: this question does not make much sense since there does not ever seem to have been a legal definition or status of nobility in Brabant, during the period of the national Dukes.

"[10] Nicolas Joseph Stevens concluded that: "even though under the Austrian regime, which in terms of prerogatives devolving to the nobility, we know the essentially formalistic spirit, the quality of Noble was denied to members of the Seven Houses, init is not any less true that they had, by the seniority of their existence and by their services rendered to the City, rights to a certain illustrious standing, which distinguished them from the rest of the bourgeoisie".

[11] Moreover, even in the Austrian period, in 1743, the description of the city of Brussels published by George Frix[12] reads: "These Noble families called Patrician are those of Steenweghe, Sleews, Serhuyghs, Coudenbergh, Serroelofs, Swerts and of Rodenbeeck; whose descendants subsist still encore without having derogated from either the nobility or the virtues of their ancestors.

Numerous rulers of Brabant among which I will cite John II and Charles I, recognised them as illustrious and wise in authentic charters of 1360 and 1469 where they gave titles of Chevaliers (Knights), Ecuiers (squires) and of d'Amis aux Sujets de leur tems (Friends to the Subjects of their tems) issued from these Noble families"[13] and he continues "The privilege particular to these Noble families is worthy of remark.

[14] Another half a century later, Aubin-Louis Millin de Grandmaison estimates that: "These families benefited from wide ranging privileges.

But, as Alfred De Ridder writes in 1896[17] the fact that for members of the Lineages, the women conferred nobility to their husbands and, according to the old saying, "the womb ennobles", damaged the nobiliary principles of the Austrian Netherlands.

[18] Empress Maria Theresa, in Article XIV of her edict of 11 December 1754 "regarding titles and marks of honour or nobility, bearing of arms, coats of arms and other distinctions" tried to give, by law, a definitive solution to this question: it was then forbidden to the Members to give to themselves and their wives titles and marks of nobility: "XIV Those admitted to patrician families or lineages of our cities, will not be allowed to carry swords, or to give themselves or their wives titles or marks of nobility, failure to respect this will result in a fine of 200 florins".

On this point, the state of the question remained unchanged in the legal order of the southern Netherlands, for the next forty years, until the abolition of all nobility and the lineage regime of Brussels by the French Revolutionary Power during the invasion of Belgian Provinces.

In reality, a personal armorial would be needed as, very often, members of the Houses modified and personalised their arms up to the 18th century, either by adding charges or by changing tinctures, etc.