oslo was established as a diocese in 1068. it was originally a suffragan of the archdiocese of hamburg-bremen, from 1104 on of that of lund and starting from 1152 on of nidaros. it then covered the (modern) counties of oslo, akershus, buskerud (except hallingdal), hedmark (except the northern part of østerdalen), oppland (except valdres), telemark, vestfold and østfold, and the province of bohuslän, and the parishes of idre and särna.