- "Catherine Langford was more than just kind and generous. She had a gift of an endless, open-minded, child-like curiosity. She saw the world not for what it was, but for what it could be, and she saw potential in people that others failed to recognize. Like her father before her, her contributions to science have changed the world more than most people know. I, for one, have no idea where I would be today if I'd never met her. She changed my life in more ways than I ever could have imagined."
- ―Daniel Jackson at Catherine Langford's funeral.
Much of her life was influenced by a curious discovery which her father made on the Giza plateau in 1928 when she was a young girl. She took her Eye of Ra medallion from the archaeological dig where he made that discovery at that time. She wore it for the rest of her life. (Stargate)
Catherine's father and her fiancée, Ernest Littlefield, did experiments on his unusual discovery in 1945. Catherine's father told her Ernest had died in an accident, but in reality he traveled through the mysterious ring to another planet and was presumed lost. (SG1: "The Torment of Tantalus")
In 1969, Catherine received a brief visit from two strangers, one of whom claimed to be the son of Heinrich Gruber, her father's partner in the original dig in Giza and researcher on the Stargate in 1945. She was able to tell her visitors where the Stargate was currently being stored. In reality, the visitors were Captain Samantha Carter and Dr. Daniel Jackson who, along with Teal'c and Colonel Jack O'Neill, had been accidentally transported back in time. It's possible that Jackson and Carter's visit prompted Catherine to begin pressing the military to reopen its research on the Stargate. By this time, her father had died. (SG1: "1969")
In 1995, she hired Daniel Jackson, who discovered through translation that the artifact which her father had discovered was called a Stargate. Later, through linking star signs with glyphs on the object, they made it work for the second time. which was the first time as far as Catherine or anyone else involved in Project Giza knew. She gave Daniel her medallion for good luck when he went through the gate. He sent it back to her with O'Neill and when he next saw her, she had in fact gotten it back. (Stargate)
In 1997, Daniel discovered that Ernest Littlefield was still alive and informed Catherine. She accompanied SG-1 to the planet Heliopolis. Once there she was reunited with Ernest and they traveled back to Earth together. (SG1: "The Torment of Tantalus")
Catherine died in 2005. Many of her possessions were left to Daniel, including her Eye of Ra medallion and her entire collection of artifacts which ultimately led to the discovery of a Zero Point Module. Her niece Sabrina Gosling said that Daniel was like a son to her. (SG1: "Moebius, Part 1")
- In an alternate reality visited by Daniel Jackson in 1998, Dr. Catherine Langford attempted to recruit the Daniel Jackson of her reality into the Stargate Program. However, he rejected her offer and she described him as being "quite rude" in doing so. She supervised the team that discovered how to make the gate work and Jack O'Neill led the first mission through the Stargate to Abydos. She continued to head the SGA until Apophis' forces invaded Earth in 1998. She was killed in the invasion of Cheyenne Mountain. When Daniel thanked her for helping him get home, she said since he helped the Catherine from his reality reunite with Ernest Littlefield, she considered them even in the grand scheme of things. (SG1: "There But for the Grace of God")
- Claims to have been 21 years old in 1945, placing her birth in 1923/1924.
- In "Full Circle," Daniel has her Eye of Ra medallion while Ascended and claims she gave it to him, but he later gets it from her after her death. This discrepancy is never addressed.