In 1998, Strughold called a meeting of the Syndicate to be held in London after a new mutated strain of purity was discovered. At this meeting, the group was informed that the colonization agreement with the greys appeared to be a lie. Strughold proposed to continue cooperating with the greys anyway in order to buy time to develop the vaccine. He also proposed to kill Fox Mulder (who had seen the new purity strain), or someone close to him.
After the X-Files were re-opened, the Cigarette Smoking Man personally delivered this news to Strughold in Foum Tataouine. Strughold was tired of constantly hearing the name "Mulder," but doubted that Mulder was a threat, as he was only one man. (The X-Files Movie)
The script of The X-Files Movie describes Strughold as "a small lean man with close-cropped hair. He is at once elegant and imposing with eyes that hold you with laser-like acuity." It is probable that, in reality, this character was named for Nazi scientist Hubertus Strughold, who experimented on Jews during World War II and was sent to the United States of America as part of Operation Paper Clip. In the final version of the film, the character was portrayed by Armin Mueller-Stahl.
No episodes of The X-Files reference Strughold himself and he appears only in the movie, though it is mentioned in the episode "One Son" that Diana Fowley had spent considerable time in Tunisia, which may have been because she was working for Strughold at the time. It is likely the Strughold Mining Company was named for him. The fact he does not appear in a scene in "One Son", in which the Syndicate is destroyed by faceless aliens, means it is unknown whether he survived or perished in the attack.
The film does not establish why Strughold is based in Tunisia but, in a secret track on The X-Files: The Album, Chris Carter says that, by 1990, the Syndicate's "only orders would be taken from a man named Strughold, a German industrialist who had fled his homeland to northern Africa." Though this statement refers to Strughold as being the leader of the Syndicate, his exact position in the group is not established in the film.