by @Chris
Brabant has been three different things under one name: a Frankish pagus between the Scheldt and the Dijle, a duchy (1183–1795) that reached from Nivelles to 's-Hertogenbosch, and since 1815 a set of provinces in two countries: Noord-Brabant, Antwerp, Flemish Brabant, Walloon Brabant and Brussels. The map follows its pieces (districts and quarters, later arrondissements) from the Nervii and the counts of Leuven through Burgundy, the Habsburgs, the Dutch Revolt and the split of 1648, the French départements and the Belgian Revolution to the three-way split of 1995. Colours show who ruled each piece: brick red the dukes of Brabant, purple Burgundy, gold Habsburg and Austria, green Spain, orange the Dutch States and the Netherlands, blue France, crimson the United Belgian States and Belgium. Neighbours are pale. Borders before about 1100 are indicative reconstructions from dioceses and rivers. Borders from 1183 to 1795 are built from the parishes of the Historical Atlas of the Low Countries (situation 1500); later borders from Belgian NIS municipality codes and Dutch municipalities. Small or short-lived changes are simplified. Sources: Historical Atlas of the Low Countries and the Duchy of Brabant GIS collection (R. Stapel, IISG, CC BY-SA 4.0); hertogdombrabant.nl (Damen et al., 2021); nl/fr/en Wikipedia on the pagus and landgraviate of Brabant, the duchy, the Generality Lands, the Lands of Overmaas, the départements and the provinces; gemeentegeschiedenis.nl; Statbel; Natural Earth.
Nervii · their civitas (indicative) · Menapii · their civitas (indicative) · Eburones → Tungri · civitas Tungrorum (indicative) · Aduatuci (indicative) · Toxandria (Salian Franks) · Pagus of Brabant (Brabantgouw) · Pagus of Hesbaye (Haspengouw) · Pagus of Rien (Antwerp) · Pagus of Hainaut · Pagus of Lomme (Namur) · Pagus of Maasgau (Masau) · County of Flanders · County of Hainaut · County of Namur · Prince-Bishopric of Liège · Duchy of Guelders · County of Holland · County of Zeeland · Bishopric of Utrecht · Duchy of Cleves · Duchy of Jülich · Electorate of Cologne · Other lordships · France (annexed lands) · Batavian Republic → Netherlands · German lands · Kingdom of Belgium · Luxembourg · Landgraviate of Brabant (1085–1183) · Leuven · county → quarter → arrondissement · District of Tienen · Brussels · county → quarter → capital region · Halle-Vilvoorde · Walloon Brabant · Roman Pays → province · Antwerp · margraviate → quarter → province · Antwerp — held by Flanders · Antwerp — held by the Netherlands · Antwerp — held by Spain · Antwerp — held by the States · Mechelen · lordship → arrondissement · Breda & Bergen op Zoom · west Noord-Brabant · Breda & Bergen op Zoom — held by France · Breda & Bergen op Zoom — held by Spain · 's-Hertogenbosch · Meierij → Noord-Brabant · Land van Cuijk & Grave · Duchy of Limburg · Duchy of Limburg — held by France · Lands of Overmaas & Maastricht · Lands of Overmaas & Maastricht — held by France · Lands of Overmaas & Maastricht — held by Spain · Lands of Overmaas & Maastricht — held by the States · Free lordships (Ravenstein, Megen, Gemert, Boxmeer…)