In 1902, he moved to Germany to work for the satirical magazine Simplicissimus in Munich after editor Albert Langen had been in contact with author Bjørnstjerne Bjørnson looking for Norwegian talent.

In 1933 the art academy in Berlin arranged a special exhibition to celebrate Gulbransson's 60th birthday, which was shut down by the Nazi party after only two days.

Simplicissimus editors Franz Schoenberner and Thomas Theodor Heine have claimed that Gulbransson actively cooperated with the Nazis from 1933 on, and this co-operation was sharply criticized by the writer Klaus Mann.

[2] During World War II, after his own home country was occupied by the Germans, he produced caricatures against the Allies, in particular against Winston Churchill.

His 1906 marriage to Grete Jehly produced a son, Olaf Andreas Gulbransson, who became a noted church architect.