Haagen Krog Steffens (30 April 1873 – 9 May 1917) was a Norwegian historian, archivist and genealogist.Haagen Krog Steffens was born in Christiania (now Oslo), Norway.
He was the son of physician Henrich Steffens (1841-1984) and Asta Falch.
Steffens belonged to a family originating in Holstein.
Both his father and grandfather were doctors and his family fostered a number of prominent individuals.
Steffens attended Christiania Cathedral School (now Oslo Cathedral School).
Steffens graduated with a Candidate of Law degree in 1897.
Later he indertook 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 and had a decisive influence on the archive system.
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 was a published in both Morgenbladet and Aftenposten.He is best known as a very diligent genealogist.
He wrote genealogies of several families, including the Mogensen, Mathiesen, Rod and Aall families.He died in Oslo and was buried at VÃ¥r Frelsers gravlund.