The primary source which confirms his parentage has not yet been identified.
Herr von Heinsberg. Friedrich [I] Archbishop of Köln confirmed donations to Kloster Dunwald and shared the Vogteischaft with "comitis Adolphi" by charter dated 1118 witnessed by "Adolfus comes de Monte et frater eius Euerhardus, Gerardus comes de Wassenberg […et filius eius Gerardus], Theodericus comes de Thonburch, Theodericus comes de Ara, domnus Goswinus de Hennesberg et frater eius Gerardus…Gerardus de Wyckerode…".
Heer van Valkenburg 1119. 1
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