The Count of Hainaut was the ruler of the county of Hainaut, a historical region in the Low Countries (including the modern countries of Belgium, the Netherlands, Luxembourg and parts of northern France and western Germany). In English-language historical sources, the title is often given the archaic spelling Hainault.
The Count of Hainaut was then divided between the cities of Mons and Valenciennes.
Counts of Mons
Counts and Margraves of Valenciennes
Valenciennes and Mons are once again reunited in a consolidated County of Hainaut.
Charles II proclaimed the Pragmatic Sanction of 1549 eternally uniting Hainaut with the other lordships of the Low Countries in a personal union. When the Habsburg empire was divided among the heirs of Charles V, the Low Countries, including Hainaut, went to Philip II of Spain, of the Spanish branch of the House of Habsburg.
Between 1706 and 1714 the Low Countries were invaded by the English and the Dutch during the War of the Spanish Succession. The fief was claimed by the House of Habsburg and the House of Bourbon. In 1714, the Treaty of Rastatt settled the succession and the County of Hainaut went to the Austrian branch of the House of Habsburg.
The title was factually abolished in the aftermath of the French revolution and the annexation of Flanders by France in 1795. Although, the title remained officially claimed by the descendants of Leopold II until the reign of Charles I of Austria.
In the modern Kingdom of Belgium, the title of "Count of Hainaut" was traditionally given to the eldest son of the crown prince, who was himself styled "Duke of Brabant". In 2001, with the birth of Princess Elisabeth of Belgium (now Duchess of Brabant), heir and eldest daughter of Prince Philippe, Duke of Brabant (now Philippe, King of the Belgians), it was decided not to feminize and award her the title of Countess of Hainaut, but to abolish it.