Mezue ahịrịokwu na - esonụ: Aha mbụ e si n'asụsụ Irish nweta ebe obodo a dị ugbu a bụ, nke pụtara " osisi oak nke Calgach " n'asụsụ Old Irish, nke e si n'aha onye ọgọ mmụọ a na - amaghị ama nweta. John Keys O'Doherty, Bishọp Roman Katọlik nke Derry site na 1889 ruo 1907, gbalịrị ịchọpụta Calgach na onye mmegide Agricola bụ Calgacus, ebe Patrick Weston Joyce na-ekwu na "Calgach", nke pụtara "onye agha dị egwu", bụ aha a na-akpọkarị. E guzobere ụlọ ndị mọnk ndị Celtic na narị afọ nke isii; Adomnán kpọrọ Saint Columba dị ka onye guzobere ya. A gbanwere aha ya ka ọ bụrụ "Daire Coluimb Chille", "osisi oak nke Columba", nke mbụ a kpọtụrụ aha na Annals of Ulster maka 1121. Ka ebe obibi ndị mọnk ahụ na-ebuwanye ibu, a gụpụrụ aha ahụ ịbụ nanị "Doire" (nke a na-akpọzi). Nke a mechara bụrụ "Derry". N'afọ 1604, "Derrie" nwetara akwụkwọ ikike mbụ ya dị ka obodo na ngalaba nke obodo site n'aka James nke Mbụ nke England. Ihe
Cahir O'Doherty, onye isi ndị Irish nke Inishowen, bibiri ebe obibi ahụ na 1608.