Career
During World World War II he was a courier for Milorg. His dr.philos. thesis from 1959, Hjemmestyrkene. Hovedtrekk av den militære motstanden under okkupasjonen, has been an inspiration for later works by other historians.
He was a son-in-law of Daniel Grini, and together with Ellen Helvig Grini (1918–2001) he had the son, historian Knut Kjeldstadli.
He died in March 1961 and was buried in Ullern.
