Haagen Krog Steffens was a Norwegian historian, archivist and genealogist.

Haagen Krog Steffens was born in Christiania

Oslo

Oslo is a municipality, as well as the capital and most populous city in Norway. As a municipality , it was established on 1 January 1838. Founded around 1048 by King Harald III of Norway, the city was largely destroyed by fire in 1624. The city was moved under the reign of Denmark–Norway's King...

, the son of physician Henrich Steffens (1841-1984) and Asta Falch. Steffens belonged to a family originating in Holstein

Holstein

Holstein is the region between the rivers Elbe and Eider. It is part of Schleswig-Holstein, the northernmost state of Germany....

. Both his father and grandfather were doctors and his family fostered a number of prominent individuals.

Steffens attended Christiania Cathedral School. Steffens graduated with a Candidate of Law degree in 1897. Later he had a series of studies at archives in Sweden, Denmark, Germany and Belgium. He was hired was an archivist in the National Archival Services of Norway

National Archival Services of Norway

The National Archival Services of Norway is a Norwegian government agency that is responsible for keeping state archives, conducts control of public archiving and works to preserve private archives. It is subordinate to the Ministry of Culture and Church Affairs and consists of the National...

 and had a decisive influence on the archive system. He is best known as a very diligent genealogists.

His most important works were Norske slægter, released in two volumes in 1912 and 1915; Den norske Centraladministrasjons Historie 1814-1914, released in 1914; and Kragerø bys historie, released in 1916. He wrote genealogies of several families, including the Mogensen, Mathiesen

Mathiesen

Mathiesen is a Danish-Norwegian patronymic surname meaning "son of Mathies" . Several spelling variants are used, including Matthiesen, Matthiessen, Mathisen, Matthisen...

, Rod and Aall

Aall (Norwegian family)

Aall is a prominent Norwegian family, originally from Aal in Jutland . The family can be traced back to ca. 1500. Niels Aall immigrated in 1714 to Norway, where he became a wealthy merchant and ship-owner in Porsgrunn-Famous members:...

 families. He was a published in both Morgenbladet

Morgenbladet

Morgenbladet is a Norwegian weekly newspaper. It was founded in 1819 by the book printer Niels Wulfsberg, and was the country's first daily newspaper. For a long time, it was also the country's biggest newspaper. It was closed down by the German Wehrmacht during World War II...

and Aftenposten

Aftenposten

Aftenposten is Norway's largest newspaper. It retook this position in 2010, taking it from the tabloid Verdens Gang which had been the largest newspaper for several decades. It is based in Oslo. The morning edition, which is distributed across all of Norway, had a circulation of 250,179 in 2007...

.

Selected works

• Hvitebjørn og Stubljan – En norsk Gaards og Slægts Historie (1898)
• Linderud og slegterne Mogensen og Mathiesen (1899)
• Selvig i Hurum – Et stykke norsk Gaards og Slægts Historie (1902)
• Slegten Wiel (1903)
• Herrebø Fayancefabrik og dens grundlægger Peter Hofnagel (1904)
• Slegten Stang – Bidrag til Fredrikshalds Historie (1905)
• Fru Emerentze Munch, f. Barclays Optegnelser (1907)
• Slegten Aall (1908)
• Fru Conradine Dunkers Erindringer (1909)
• Norske Slægter 1912 (1912)
• Den Norske Centraladministrations Historie 1814–1914 (1914)
• Norske Slægter 1915 (1915)
• Kragerø Bys Historie 1666–1916 (1916)