[1] The Channel Islands are mentioned in the Antonine Itinerary as the following: Sarnia, Caesarea, Barsa, Silia and Andium, but Jersey cannot be identified specifically because none corresponds directly to the present names.
Theoretically, if Caesarea was originally pronounced with a "k", that may have naturally developed into a "g" sound for locals (or foreigners), making Gersei, Gersoi, or the other spellings relatable.
Because "g" is pronounced as both a hard guttural "g" as in "go" and a soft "j" as in "gym" or "gem", the spelling of Jersey could be a result of the variance in its pronunciation.
[28][29] Angia could be a misspelling for *Augia, that is the Latinized form of Germanic *aujō (> Old English ī(e)ġ > is-land),[30] that could have extended before the Viking Age along the coast of France, as for île d'Yeu (Augia, Insula Oya) or Oye-Plage (Ogia 7th century) and constitutes the suffix -ey in Jersey, Guernsey (Greneroi), Alderney (Alneroi) and Chausey (Calsoi).
[31] Chausey can be compared with Cholsey (GB, Berkshire, Ċeolesiġ 891), interpreted by Eilert Ekwall[32] as "Ċeola 's island".