Passage: Educated in Córdoba, as a guest at the court of the Emir of Córdoba, García was the son of Íñigo Arista, the first king of a Basque dynasty ruling in Pamplona up to the late 9th century. When his father was stricken by paralysis in 842, he became regent of the kingdom (or perhaps co-regent with his uncle Fortún Íñiguez). He and his kinsman Mūsā ibn Mūsā ibn Fortún of the Banu Qasi rebelled against the Cordoban emir in 843. This rebellion was put down by Emir Abd ar-Rahman II, who attacked the Kingdom of Pamplona, defeating García badly and killing Fortún. At his father's death in 851/2 (237 A.H.), he succeeded to the crown of Pamplona.

Question: What was the name of Garcia's relative who went against the Cordoban emir with him?
Mūsā ibn Mūsā ibn Fortún