He was born in Roermond, Netherlands in 1869 as the son of an ethnically German newspaper editor. He worked for the Algemeen Handelsblad from 1906 to 1909. His graphic cartoons depicted the rule of the German military in Belgium, portrayed the Germans as barbarians and KaiserWilhelm II as an ally of Satan. The German government offered a reward of 12,000 guilders for Raemaekers, dead or alive. The German government forced the Dutch government to place Raemaekers on trial for 'endangering Dutch neutrality', but he was acquitted.
He later left for England because of the bounty on his head. There, his work was published in The Times and he released a collection, Raemaekers Cartoon History of the War, in 1919. 150 of his works toured the United Kingdom and France in an exhibit.