He is married to Nn de Chiny.
They got married
THIERRY [II] de Walcourt (-[8 Apr 1235/12 Jun 1237]). “Werricus de Walecurt comes Montis acuti et Clarimontis” donated “pratum de Roseriis...et...sartum de Strivel” to Val-Saint-Lambert, in the presence of “Tirricus et Jacobus filii mei...Tirricus de Hufalise filius sororis meæ...” by charter dated 1204[1117]. “Wirricus dominus de Walcourt” donated “molendinum de Goustal” to Justémont, with the consent of “conjugis meæ Gerbergæ...et filiorum meorum Wirrici, Ægidii, Theodorici et Jacobi et cæterorum”, by charter dated 29 Jun 1206[1118]. Comte de Montaigu: “Theodericus de Walcourt…comes Montisacuti” transferred “feodum de Mahagne” to “domino Philippo marchioni Namucensi” by charter dated 1211[1119]. It is unclear whether the absence of later sources, in which Thierry is referred to as comte de Montaigu, indicates that he relinquished the title or his claim to the county. Seigneur de Walcourt. “Theodericus dominus de Walcuria” renounced rights over “cœnobium de Jardinio beatæ Mariæ juxta Walcuriam sitam”, with the consent of “uxore mea domina Gertrude”, by charter dated Dec 1232[1120]. “Terric seigneur de Walcourt et Gertrude son épouse” declared that they had sold property “à Houdeng, Gœgnies et Haine”, bought from “Amalric fils de Thierry”, to Rœulx abbey by charter dated Jul 1234[1121]. “...Th. de Valecourt et des deux fils...” promised to guarantee the agreement regarding the succession to the county of Flanders by charter dated Jan 1234 (O.S.?)[1122]. “...Th. de Walcourt et duo filii eius...” and others requested the archbishop of Reims to confirm their agreement regarding the Flanders succession by charter dated [Feb] 1235, confirmed before 8 Apr 1235 by the archbishop[1123].
m firstly ([1200]) --- [de Chiny, daughter of LOUIS [III] Comte de Chiny & his wife Sophie ---]. “Theodoricus dominus de Walcurt”, on his marriage “cum filiam comitis Ludovici” whose dowry was “terræ de Urgeou”, confirmed rights “super...silvæ...Forest”, disputed by “patre uxoris meæ”, to Orval by charter dated 1200[1124]. The chronology suggests that “comes Ludovicus” was Louis [III] Comte de Chimay, although if that is correct it is somewhat surprising that this charter does not refer to him as deceased. The relationship between the Walcourt and Chiny families is also indicated by the dispensation (see below) required for the marriage of Gilles Seigneur de Walcourt, son of Thierry, with the widow of Gilles Seigneur de Hierges, who was descended from Alix de Chiny (supposed paternal aunt of the wife of Thierry de Walcourt). m secondly ---. Roland suggests that the mother of Thierry’s [younger] children was an otherwise unrecorded second wife. He says that “selon toute apparence” she belonged to “la noble famille de Strépy en Hainaut”, citing a charter dated 1204 which confirms that they owned property at Houdeng and Gœgnies: “Baouduin de Strépy” granted “le pâturage de ses alleux de Houdeng et Gœgnies” to Alne abbey by charter dated 1204[1125]. In addition, “Alard seigneur de Strépy” issued a charter dated 1232 relating to the “l’alleu de Houdeng-Gœgnies-Haine”[1126]. Her dowry was Houdeng, Gœgnies and Haine, as shown by the charter dated 1232 under which “Gilles seigneur de Barbançon” notified that [her son] “Amalric custos de Walecuria” had transferred to his father “l’alleu de Houdeng-Gœgnies-Haine qui lui revenait de sa mère”[1127]. “Th. dominus de Walecourt et G. uxor mea” sold property “apud Housdaing, apud Gognies et apud Hainne” to Rœulx abbey, including property sold by “Amolrico filio meo” and inherited from “matre sua que fuit uxor mea”, with the consent of “Theodorici et Amolrico filii mei” and signifying “filiam...in Romanie partibus” whom they wished would consent later, by charter dated May 1234[1128]. m thirdly as her second husband, GERTRUDE, widow of ---, daughter of --- (-[Jul 1234/7 Dec 1240]). “Theodericus dominus de Walcuria” renounced rights over “cœnobium de Jardinio beatæ Mariæ juxta Walcuriam sitam”, with the consent of “uxore mea domina Gertrude”, by charter dated Dec 1232[1129]. “Th. dominus de Walecourt et G. uxor mea” sold property “apud Housdaing, apud Gognies et apud Hainne” to Rœulx abbey, including property sold by “Amolrico filio meo” and inherited from “matre sua que fuit uxor mea”, with the consent of “Theodorici et Amolrico filii mei” and signifying “filiam...in Romanie partibus” whom they wished would consent later, by charter dated May 1234[1130]. “Terric seigneur de Walcourt et Gertrude son épouse” declared that they had sold property “à Houdeng, Gœgnies et Haine”, bought from “Amalric fils de Thierry”, to Rœulx abbey by charter dated Jul 1234[1131]. She is named as decased in the 7 Dec 1240 of her daughter, quoted below. Thierry [II] & his first wife had two children:
a) GILLES de Walcourt (-[1 Aug 1248/1252]).
b) IDA de Walcourt (-1257, bur Aulne).
https://fmg.ac/Projects/MedLands/NAMUR.htm#WeryWalcourtMGerbergeMontaigu