The primary source which confirms his parentage has not yet been identified. Monlezun names "Dato-Lupi" as son of Loup Donat, specifying that he succeeded his father as Comte de Bigorre. 1
According to Jaurgain, the husband of Lupa Sánchez was Dato [II] Loup Comte de Bigorre but he cites no primary source on which this is based. 2
Marriage Information:
Dato married Lupa Sánchez DE NAVARRA, daughter of Sancho I García DE NAVARRA and Unknown Mistress.
Sources
1 Foundation for Medieval Genealogy, Medlands, Donat Loup.