He was a son of the powerful magnate Rodrigo Velázquez and his wife Adosinda and is usually associated with the conflicts surrounding the accession of Vermudo II after a Galician rebellion in 982.
There is disagreement in the primary sources (narrative and documentary) over when and how Pelayo came into the see of Iria, though both the Historia Compostelana and the Chronicon Iriense[1] agree that he was elevated immediately after the death of Sisnando Menéndez (29 May 968) by an aristocratic party, but was afterwards forcibly expelled from the see by Vermudo II (982).
According to the Chronicon: Mortuo Sisnando, Pelagius, Lucensis episcopus, Ruderici comitis filius, in Locum Sanctum nonus a dominis et senioribus rogatus adducitur.
Sed cum comites et potestates Galletie patrem non bene rectum nec filium, flores iuventutis adultum, ergo se amicos non senserunt, tunc accepto consilio, Ueremudum iuvenem Ordonii regis filium quondam, apud inclitam beati Iacobi urbem educatum, in regiminis excellentis sublimare conantur, in era Ma XXa.
[2] According to the Historia: Después de Sisnando, obtuvo la mitra de este obispado mediante el poder secular, un hijo del conde Rodrigo Velázquez llamado Pelayo [Pelagius … filius comitis Ruderici Velasqui], que ni se cuidó del cargo recibido ni se humilló como debía a su Creador ... por lo cual no permitiendo la divina Providencia que ocupara injustamente la iglesia por más tiempo, fue expulsado por el rey D. Bermudo.
[6] Another document from Celanova, dated 7 August 969, has been controversially redated by Rubén García Álvarez to 968 in order to support the reality of Pelayo's episcopacy.
Their chief rival clan was led, during Pelayo's episcopate, by Gonzalo Menéndez, who supported first Ordoño III, later his son Vermudo II.
[10] According to a theory advanced by Justo Pérez de Urbel and followed by García Álvarez, it was only three years after his coronation (and after Ramiro's death in 984) that Vermudo had sufficient power to depose Pelayo.
Nevertheless, on 30 May 985 Pelayo was present in his own cathedral at a court presided over by Vermudo; and on 6 June he confirmed a gift alongside the king to the monastery of San Paio de Antealtares by count Tello Aloitiz and his wife Mummadomna.
Pelayo was capable of good Latin, as two charters with unprecedented formulae (23 October 978 and 11 September 982) indicate, and was well-versed in the Holy Bible, facts which call into question the Chronicon's characterisation of him as "secular" and of little knowledge.