Otto Bahr Halvorsen

Halvorsen was born in Kristiania (now Oslo, Norway) to Otto Hellen Halvorsen (1840–1921) and Karine Christine Christiansen (1847–1927). He attended Kristiania Cathedral School. He studied law at the University of Kristiania where he completed his examen artium in 1890. As a licensed attorney, in 1904 he opened a law firm in Kristiania.

In 1899, he was married to Kathrine Hofgaard (1875–1960), daughter of Simon Wright Hofgaard and Ida Mathilde Aars.

In 1912 Halvorsen was first elected to the Storting from the neighborhood of Gamle Aker in the district of St. Hanshaugen in Kristiania.

Halvorsen served Kristiania in the Parliament from the Conservative Party from 1913 to 1923. He became Prime Minister during 1920 while also serving as Minister of Justice. He again became Prime Minister in May 1923 while simultaneously serving as Minister of Justice. Between these terms, Halvorsen was leader of the Conservative Party in Parliament and President of the Storting (stortingspresident). However, he became gravely ill in March 1923, just a few days after forming his government, and died of cancer on the 23rd of May that same year.