He was the brother of King Sancho I Garcés and son of García Jiménez by his second wife, Dadildis of Pallars.
[2] In 927, Jimeno took an army south to support Muhammad ibn Lubb ibn Muhammad of the Banu Qasi against the Córdoba-allied Banu Tujib, and Jimeno's presence there forced Abd-ar-Rahman III, Emir of Córdoba to retreat without offering battle.
[2] A document in the archives of the monastery of San Juan de la Peña confirming a boundary settlement reached under King Fortún Garcés was issued when "[the aforementioned King] Jimeno Garcés was ruling with his ward the Lord García in Pamplona and in [Deyo].
"[4] Upon his death in 932 or 933 his nephew, now García Sánchez I of Pamplona, ruled alone under the tutelage of his mother Toda, who was doubly Jimeno's sister-in-law.
Sancha and Jimeno had three children: García, who went with his mother to Gascony; Sancho, who married Quissilo, daughter of García, count in Bailo; and Dadildis, wife of Muza Aznar, son of the wali of Huesca, al-Tawil, and grandson of Aznar Galíndez II of Aragon.