He was born in Stockholm as a son of professor of geology Waldemar Christofer Brøgger (1851–1940) and Antonie Scheel Siewers (1854–1933).
Without a formal examination, he wrote the paper Øxer av Nøstvettypen, which was published in 1905 by the Norwegian Geological Survey.
He wrote a book on the city's medieval history and founded the local branch of the Society for the Preservation of Ancient Norwegian Monuments.
He also contributed via the Institute for Comparative Research in Human Culture, and was a driving force in establishing the Viking Ship Museum.
[5] He edited the journals Oldtiden, St. Hallvard and Acta Archaeologica, and was also a co-editor for volumes seven through ten of the biographical dictionary Norsk biografisk leksikon.
[6] Among his most important works is Ertog og øre (1921), where he combined archeological findings with law texts from the Gulating and Frostating.
Shortly after the Second World War broke out in 1939, Brøgger initiated a rescue operation to save the most important items from Oldsaksamlingen, which were secretly evacuated and placed in a bank safe at Fagernes.
[15] Unlike the ordinary board members Harald Grieg, Johannes Sejersted Bødtker and Francis Bull,[13][14] he was not sent to Grini concentration camp, but was held at the prison on Åkebergveien between 28 June and his release on 2 July.
[4] However, Brøgger was arrested for a second time in September 1941, together with fellow academics Otto Lous Mohr and Didrik Arup Seip.