Complex sentence: At the outbreak of the Second World War, Borthen went to London, England, later to Argentina where he worked in the Norwegian embassy in Buenos Aires as press attaché from 1945 until 1950.
Split into simpler sentences: At the outbreak of the Second World War, "Borthen" went to London, England. He then went to Argentina where he worked in the Norwegian embassy in Buenos Aires as press attaché staying there from 1945 until 1950.