The Gesta Episcoporum Cameracensium names "Rainero…Raineri filio" as "Lantbertus…nepote suo". His parentage is confirmed by the Chronicle of Alberic de Trois-Fontaines which names "filius eius [=comite Raginero Montense] iunior Ragynerus" when recording that he succeeded his father.
He succeeded his father in 1013 as REGINAR [V] Comte de Hainaut, Comte de Mons. The Chronicle of Alberic de Trois-Fontaines records that in 1015 "Raginerus comes" fought with his uncle "Lambertus Lovaniense" at Florinnes, specifying that his uncle was killed in the battle. The dating clause of the charter dated to [1027/39], under which "Evrardus…atque Fredescensis uxor mea" donated land "in Asquilleyas" to the monastery of Saint-Ghislain, names "Ragnieri comitis Castriloci montis". 2