In the penultimate year of World War II, Broom discovered the infant Hellboy and raised him as if he were his son.
In the 2004 Hellboy movie, John Hurt’s Broom discovered Hellboy while stopping Project Ragna Rok, but the professor was killed circa 2004 by Rasputin’s minion, Karl Ruprecht Kroenen.
We’ll have to wait and see Ian McShane’s Broom will also have participated in World War II or if his early experiences will move forward a decade or two to better sync up with contemporary times.
In the comics, Professor “Broom” was a member of the British Paranormal Society, and he used his knowledge of the occult and supernatural to help the Allies combat the Nazis and their black magic.