Gautaz derived from the Proto-Germanic geutaną, meaning "to pour" which could allude to watercourses in the land where the Geats were living. This same root may be connected to the name of the Swedish river Göta älv at the city of Gothenburg. The earliest mention of the Geats was possibly made by Ptolemy in the 100s AD ("doutai" or "goutai") or in the 500s by Jordanes ("gauthigoth") and Prokopios ("gautoi")
The Geatish ethnonym *gautaz is probably related to the ethnonym of the Goths and of the Gutes (inhabitants of the island of Gotland), deriving from Proto-Germanic *gutô (cf. Gothic Gut-þiuda, Old Norse gotar or gutar).
Some medieval chroniclers referred to the Geats as Goths and confused the two.
The German chronicler Johannes Aventinus (ca. 1525) reported Gothus as one of 20 dukes who accompanied Tuisto into Europe, settling Gothaland as his personal fief, during the reign of Nimrod at Babel. The Swede Johannes Magnus around the same time as Aventinus, wrote that Gothus or Gethar, also known as Gogus or Gog, was one of Magog's sons, who became first king of the Goths (Geats) in Gothaland. Magnus separately listed Gaptus as son and successor of Beric, first king of the Goths south of the Baltic.
Gautr is also one of the Eddaic names of Odin in Norse mythology, but also as an alternative form of the name Gauti, who was one of Odin's sons, and the founder of the kingdom of the Geats, Götaland (Gautland/Geatland), in Bósa saga ok Herrauðs (c. 1300). This Gautr/Gauti also appears as the father of the recurrent and undatable Geatish king Gautrekr in that saga, and several other sagas produced between 1225 and 1310.
Some versions of the English royal line of Wessex add names above that of Woden, purportedly giving Woden's ancestry, but the names are now usually thought be from another royal lineage erroneously added to the standard genealogy.
Some of the genealogies end in Geat, who, it is reasonable to think, might be Gaut, but others continue with Geat's father, Tatwa, and even further. In the Life of Alfred (893), Asser states that the pagans worshipped Geat himself, for a long time, as a god. He quotes a disdainful verse attributed to Coelius Sedulius (5th century).
The 10th-century poem of Deor briefly mentions Geat and his wife, Maethehilde. The account in the Historia Britonum (c. 835; generally attributed to Nennius) says that Geat was considered the son of a god by the heathens of England. Elsewhere, it names Gothus, a son of Armenon, as the Goths' ancestor.