Kadiatu Lethbridge-Stewart was the only existing prototype of a next-generation human super soldier program conducted in the years following the Thousand Day War (2086-2088). Kadiatu was related by adoption to a branch of the Lethbridge-Stewart bloodline which arose from an affair that Alistair Gordon Lethbridge-Stewart conducted during his posting as a lieutenant in Africa. Kadiatu was his great-great-great-great-granddaughter.
Kadiatu was born in the Imogen R&D facility in Leipzig. After the project was destroyed at the behest of the underworld figure the Angel Francine, she was adopted as a three month old baby by the man responsible, Brigadier Yembe Lethbridge-Stewart, when he found himself unable to euthanase her. She grew up in Makeni, a hick town in the West African forest, surrounded by veterans of the Thousand Day War. As a child, she was subjected to psychological suppression techniques to minimise the expression of her ubersoldaten qualities. Around the age of eight she was rescued from drowning when her father hauled her out of the water by her hair. (PROSE: Transit)
In the mid 2110s, she was an engineering student at the Lunaversity, attempting to convert the complex mathematics of the Interstitial Mass Transit System into a basis for functional time travel. Before her first encounter with the Seventh Doctor she was about half a year away from establishing the theoretical basis for a working prototype. She constructed a primitive time craft powered by nuclear detonation as part of a corporate research project. She promptly stole it. Unknown to her, using the time craft punched holes in the fabric of space-time, creating anomalies and allowing all manner of species to move through space and time. (PROSE: Set Piece)
In 1754, the Seventh Doctor found her in a feral state on a British slaver ship. She had killed everyone on board. He sedated her and took her to the People's Worldsphere, where he asked aM!xitsa to watch over her. He returned three months later and placed her fate in the hands of Bernice Summerfield, who decided she could be rehabilitated instead of euthanised. Kadiatu subsequently developed safer time travel technology and became a temporal agent for the People, with aM!xitsa accompanying her. (PROSE: The Also People)
Kadiatu later attended Bernice Summerfield and Jason Kane's wedding in Cheldon Bonniface on 24 April 2010, where she met her adoptive ancestor Alistair Gordon Lethbridge-Stewart. (PROSE: Happy Endings) She later gave Bernice a temporal lift to the house on Allen Road in 1997. (PROSE: The Dying Days)
She reunited with Bernice Summerfield for a trip to Earth in 2606. The two women uncovered a plot involving a clone of the President of Earth taking the place of the President of Earth. Kadiatu killed a clone of herself during this debacle. (AUDIO: The Final Amendment)
Kadiatu was tall, physically well-conditioned and dark skinned. She had coal black irises. She had lower baseline metabolic and oxygen requirements, manifesting in slowed breathing and heart rates, that would lead to coma-like conditions in ordinary humans. Her physical and mental reflexes were heightened with her strength and endurance. She had a functional appendix, which allowed her to derive peak nutritional value from a wide variety of foods. As a trade off, she would eat more frequently. Her heart, liver and lungs were also larger than standard human organs, while the robustness of her immune system was increased along with her bone density.
As a student she wore cotton hair extensions, through which were woven data crystals and electronic counter measure devices.
Despite being the child of a military family, she had no combat training, but found herself responding with instinctive proficiency in unarmed combat and the use of arms. She showed no ethical or moral reaction to taking a life in combat.[source needed]