Doctor and professor in archaeology, credited with the modern-day discovery of the Stargate -- though he seems to have died never knowing just what the device is. Langford headed the expedition on the Giza Plateau, Egypt, and was present with his daughter Catherine when the Stargate was unearthed from the sands in 1928.
He spent subsequent decades studying the artifact along with his partner Dietrich and, as she grew into a young woman, his daughter Catherine. Langford initially hypothesized that the mysterious object was made of melted meteorite. Eventually he concluded (rightly) that the artifact is, in fact, a piece of technology.
In 1939 the Langfords were surprised by the arrival of Wilhelm Brücke, a Nazi occultist who had been searching for the mythical doorway. He managed to dial the gate and take Langford through it at gunpoint, forcing him to translate for him on the distant planet of Abydos. Eventually Langford refused to cooperate any further, and -- with Brücke killed -- he was returned to Earth with his memory of the entire event wiped by the Goa'uld Aset.
With the threat of world war looming (and his funds in Cairo running out), Langford now had the Stargate shipped across the ocean to the United States. During World War II his project came under the auspices of the United States military, who hoped it might be exploited as a weapon. But the only progress to be made was an accidental wormhole connection to the planet Heliopolis. Langford allowed Dr. Ernest Littlefield to travel through the puddle to the other side. But when the Stargate shut down it was believed Littlefield was lost. Langford never tried to open the gate again, telling Catherine that her fiancée-to-be had been killed in a lab explosion.
"Stargate" the Movie - Dr. Langford observes the recently unearthed Stargate, and is completely blown away as to the origins or purpose of the device.
Stargate Origins - More than a decade after the gate's discovery, Langford is abducted by the Nazis and taken through to Abydos -- though his memory of the entire event is eventually wiped.
The Torment of Tantalus - Langford manages to successfully open the Stargate, and sends Ernest Littlefield through the event horizon. He is eventually convinced that his fellow scientist was killed.