Hij was een telg uit het geslacht der Agilolfingers uit Beieren
↑History of Bavaria notes that the Duchy of Bavaria was established by the Franks, who " put it under the administration of a duke - possibly Frankish or possibly chosen from amongst the local leading families". However, there is nothing to suggest that Garibald was the son of the Frankish King Theodebert I, as stated in some genealogies.