He was the eldest son of Sancho II of Pamplona and Urraca Fernández and the second Pamplonese monarch to also hold the title of count of Aragon. His mother was an aunt of count Sancho García of Castile, and also of the powerful count of Saldaña, García Gómez of Carrión, and she appears to have played a role in forming a bridge between the kingdom and county.
Throughout his reign, his foreign policy seems to have been closely linked to that of Castile. In 996 he was forced to seek peace in Córdoba. In 997 during an expedition into the land of Calatayud, García killed the governor"s brother.
At the Battle of Cervera in July 1000, he joined, along with count García Gómez of Saldaña, in a coalition headed by count Sancho García of Castile that was defeated by Almanzor (that count Sancho led the group is thought to reflect García"s decline).
García Sánchez II was married to Jimena Fernández, daughter of Fernando Bermúdez, Count of Cea and a distinguished member of the highest ranks of the nobility of the Kingdom of León.
