Bermudo II of León

Both the paternal and maternal parentage of Bermudo II have been subject to scholarly debate. On the paternal side, the primary chronicle sources simply call him son of king Ordoño, without specifying which former king of that name. Traditionally his father has been identified as Ordoño III and the modern consensus agrees with this assignment, but at least one prominent modern Leonese historian, Manuel Carriedo Tejedo, has concluded that he instead was son of Ordoño IV.[7] The question is seemingly resolved by a charter in the cartulary of Santa María de Carracedo, in which Bermudo names his father Ordoño and his grandfather Ramiro, making his father Ordoño III and not Ordoño IV, the son of Alfonso.[8]

Controversy also exists over the identity of his mother. Traditionally he has been viewed as son of Ordoño III's documented wife, Urraca Fernández. Bishop Pelagius relates that Bermudo was born to a second wife of Ordoño, named Elvira, but since no such queen appears in charters or any other record outside of the Bishop's account, she probably did not exist. In a royal charter dated 5 January 999, Bermudo refers to his avo (grandfather, or by extension, ancestor), the count Gonzalo Betótez of Deza. As Bermudo's traditional pedigree would provide no such relationship, Justo Pérez de Urbel suggested that he was instead an illegitimate son of Ordoño III, with the relationship coming through his mother. Based on political considerations and a second ambiguous documented kinship, he provisionally identified the mother as either Aragonta or Guntroda, daughters of Pelayo González, count of Deza, who was son of count Gonzalo.[9] He has been followed in this by several historians, but others find the evidence lacking and retain the traditional view of his mother. The identification of Bermudo's first queen, Velasquita Ramírez, as a grandniece of count Pelayo allows the possibility that Bermudo was referring to count Gonzalo as ancestor of his wife and not his own blood ancestor,[10] but he was already divorced from Velasquita at the time he executed the charter in question.

By his first wife, Velasquita Ramírez, Bermudo left a daughter, Cristina, who married Ordoño Ramírez, son of his rival Ramiro III. Vermudo married secondly Elvira García, daughter of the Castilian count García Fernández, with whom he had three children: Alfonso, who succeeded him; Theresa; and Sancha. He also had three bastards: Elvira, Pelayo, and Ordoño, who married Fronilde, daughter of the aforementioned count Pelayo Rodríguez.