Yembe was related to the Lethbridge-Stewart bloodline through an affair that Alistair Gordon Lethbridge-Stewart had during his posting as a lieutenant in Africa. He was the great-grandson of Kadiatu Lethbridge-Stewart, the great-great-great grandson of Alistair Gordon Lethbridge-Stewart, and the adoptive father of Kadiatu Lethbridge-Stewart. He also shared a name with his great-great-great-great grandfather, the father of Mariatu and chief of the Royoke village.
Yembe was the commanding officer of the United Nations Third Tactical Response Brigade who led the company — comprised mostly Irish and Ethiopian soldiers — in the first counteroffensive strike against the Ice Warriors on Mars. The brigade dropped onto Olympus Mons, but suffered heavy casualties on the way in.
During the war, he saved a fighter pilot named Francine at the Gangis Chasma; she later became the underworld figure the Angel Francine.
In the years following the Thousand Day War, Yembe was charged with raiding and destroying the Imogen super soldier program by the Angel Francine. Ultimately, his mission was to euthanise the child the program had created, but he found himself unable to do so and instead adopted her as his child. He named her Kadiatu Lethbridge-Stewart after his great-grandmother. He raised Kadiatu in the small town of Makeni, located in the West African forest and inhabited by veterans of the Thousand Day War. (PROSE: Transit)