His reign is summed up by Justo Pérez de Urbel's description of him as "the poor king tormented in life by the sword of Almanzor and in death by the vengeful pen of a bishop."

Pelagius of Oviedo (died 1153), half of whose Chronicon covers the reign of Bermudo, is highly critical of the king.

At the time of the usurpation Bermudo II's faction was led by Gonzalo Menéndez and that of Ramiro III by Rodrigo Velázquez.

[4] Between November 991 and September 992, Vermudo was expelled from the kingdom by a revolt led by the magnates Gonzalo Vermúdez, Munio Fernández, and count Pelayo Rodríguez.

[6] On 23 August that year the village of Morella was granted to abbot Salvato of Celanova after it was confiscated because the murder of Fortún Velázquez had taken place there.

In a royal charter dated 5 January 999, Bermudo refers to his avo (grandfather, or by extension, ancestor), the count Gonzalo Betótez of Deza.

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.