Viking age geography can be traced using place names and historical sources. Oral histories from the 9th century describe early kingdoms in Norway. Viking sagas from the 1200s provide details on places, landscapes, and administrative divisions. Maps from the 16th century onward show the stability of main farm names. Combining place name registers with cadastral maps and watershed areas allows tracing of territorial units from the Viking age. Complete historical archives are needed, as pages are missing from some important protocols.