This is presumably traceable to the Germanic origins of the first family of counts, the Reginars, who had initially been installed as counts along the banks of the middle reaches of the river Maas by Emperor Lothaire in the 840s (see Grafen von Maasgau, in the document LOWER LOTHARINGIAN NOBILITY).
The existence of the series of counts named Reginar, between the early years of the 10th century and , is corroborated by many primary sources, as shown below.
The Annales Hanoni, on the other hand, specify only four counts named Reginar in the introductory Chapter VIII (in a line, father to son) and in the more detailed later chapters only three, with remarkably few details about their lives.
Information on the precise family relationships between the different counts Reginar is surprisingly sparse in the other primary sources so far consulted.
Politically, Hainaut lay within imperial jurisdiction and formed part of the kingdom of Lotharingia after the 843 treaty of Verdun.
The division of Lotharingian territories agreed 8 Aug 870 between Ludwig II "der Deutsche" King of the East Franks and his half-brother Charles II "le Chauve" King of the West Franks allocated "comitatum Hainoum" to King Charles.
As will be seen below, the evidently unreliable Annales provide the only references to key members of the family.
The county's geographic proximity to France ensured strong French political and linguistic influence in its development.
However, as with the neighbouring county of Flanders, there were jurisdictional conflicts with the empire.