- 1 September 1054. King of Navarre from 1035 until killed by his brother Ferrando at the Battle of Atapuerca.
On the death of Garcia's father, King Don Sancho el Mayor of Navarre, in 1035, the kingdom was divided among his four sons. Navarre went to Garcia; Castile to Ferrando; Huesca to Gonzalo; and Aragon to Ramiro. Civil war inevitably broke out. Garcia's assistance to Ferrando against Leon did not prevent Ferrando from invading Navarre. He killed García at the Battle of Atapuerca. Garcia was succeeded by his son, Sancho, but Ferrando eventually took the throne of Navarre for himself.
Now there was at this time war between Almocanis, King of Seville, and Almundafar, King of Granada, and with Almundafar were these men of Castille, the Count Don Garcia Ordonez, and Fortun Sanchez, the son-in-law of King Don Garcia of Navarre, and Lope Sanchez his brother, and Diego Perez, one of the best men of Castille; and they aided him all that they could, and went against the King of Seville, and when my Cid knew this it troubled him, and he sent unto them requiring them not to go against the King of Seville, nor to destroy his country, because he was King Don Alfonso's vassal; otherwise the King must defend him.