BAUDOUIN de Hainaut, son of BAUDOUIN III Comte de Hainaut & his wife Yolande van Gelre ([1110]-6/8 Nov 1171, bur Binche, Monastery of St Marie). The Chronicon Hanoniense names "Balduinum primum et Gerardum secundum" as sons of "Balduinus comes Hanoniensis" & his wife[260]. The Liber de Restauratione Sancti Martini Tornacensis names "Balduinum et Richeldem" as children of Comte Baudouin and his wife Yolande[261]. A charter dated 1117 records the donation by "comite Balduino", with the consent of "uxore sua Iola et filio suo Balduino…prefati comites fratres Ernulfus et Willelmus", of "allodium de Oberceiis" to the abbey of Saint-Denis en Broqueroie[262]. He succeeded his father in 1120 as BAUDOUIN IV "le Bâtisseur" Comte de Hainaut, minor until [1124/25]. "Balduinus Hainoniensis comes" renounced rights over "les bois de Saint-Calixte" in favour of Cysoing by charter dated to [1160], signed by "Balduini comitis, Godefridi filii eius, Eustachii del Ruth…"[263]. His brother-in-law Henri Comte de Namur et de Luxembourg named Comte Baudouin as his heir, the right to this prospective inheritance passing to his son Comte Baudouin V after he died in 1171[264]. The Chronicon Hanoniense records that "Balduinus [marito Alidis comitissa]" was buried "Bincii in monasterio sancta Marie"[265].
m ([1130]) ALIX de Namur, daughter of GODEFROI I Comte de Namur & his second wife Ermesinde de Luxembourg ([1112/14]-end Jul 1169). The Chronicle of Alberic de Trois-Fontaines names (in order) "ducissa Cyringie…Beatrix…Alidis…" as the three daughters of "comes Godefridus de Namuco" & his second wife[266]. The Chronicon Hanoniense names "Alidem…Godefridi comitis Namurcensis et Ermesendis comitisse filiam" as wife of "Balduinus comes Hanoniensis, Balduini comitis et Yolendis comitisse filiuis", in a later passage specifying that she was one of the daughters of her father's second marriage[267]. The Genealogica comitum Buloniensium names "Alithiam" as sister of "Godefridus frater Henricum", specifying that she married "Hainoensi comiti Balduino"[268], although it is chronologically impossible for Alix to have been the sister of Godefroi. The Liber de Restauratione Sancti Martini Tornacensis refers to the wife of Count Baudouin as "comitis Namucensis germanam"[269].
Comte Baudouin IV & his wife had eight children