Dee ihe na-aga n'ihu maka paragraf a - Aha mbụ nke Irish maka saịtị nke obodo nke oge a bụ, Old Irish maka "osisi oak nke Calgach", mgbe onye ọgọ mmụọ a na-amaghị. John Keys O'Doherty, Bishọp Roman Katọlik nke Derry site na 1889 ruo 1907, gbalịrị ịkọwa Calgach na onye mmegide Agricola bụ Calgacus, ebe Patrick Weston Joyce kwuru 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. E bibiri ebe ahụ.
na 1608 site n'aka Cahir O'Doherty, onye isi ndị Irish nke Inishowen.