The historical importance of Dúnlaing is his alleged role as ancestor of the powerful north Leinster dynasty of Uí Dúnlainge, which monopolised the provincial kingship from the eighth century to the eleventh and retained a local importance into the post-Norman period. Dúnlaing is said to have married Cuach, whose father Cóelbad was a dynast of Uí Bairrche of Mag Ailbe (south Co. Kildare); at the very least, this points to an early association between the Uí Dúnlainge kings and the local rulers of mid-Leinster. Cuach is named as the mother of three of Dúnlaing's sons (Illann (qv), Ailill, and Eochaid), for which her grateful husband is said to have presented her with three ringforts. The two elder sons are listed among the early kings of Leinster – the first members, it is claimed, of an enduring dynasty. Eochaid and his half-brothers Fergus, Nad Buidb, Dubthach Lethderg, and Móenach (or Óengus) Dilmenn were ancestors of minor lineages including Uí Mane of northern Leinster, Uí Fhergusa, Uí Dubtaig and Uí Móenaig.