Tradition names García Sánchez II the Tremulous as one of the Christian leaders at the 1002 Battle of Calatañazor, which resulted in the death of Almanzor and the consequent crisis in the Caliphate of Córdoba, but there is no contemporary record of him after 1000, while his cousin Sancho Ramírez of Viguera may have been ruling in Pamplona in 1002.

García was certainly dead by 1004, when his young son Sancho Garcés III first appears as king.

This gap has led to speculation as to whether there was an interregnum, while one document shows Sancho Ramírez of Viguera reigning in Pamplona in 1002, perhaps ruling as had Jimeno Garcés during the youth of García Sánchez I three generations earlier.

Sancho, born around 992 to García and Jimena Fernández, daughter of Fernando Bermúdez, count of Cea on the Galician frontier, had been raised in Leyre.

On his succession, Sancho initially rules under a council of regency led by the bishops, his mother Jimena, and grandmother Urraca Fernández.