Ubayd grew up in Granada with his sister Najma under the care of their father, since their mother had vanished when Najma was young. Their father was an influential philosopher and astronomer in the Granada court as well as a Brotherhood ally, like the rest of their family.
At some point, Ubayd himself was inducted into the Assassin Brotherhood, though he would defect to the Templar Order after. During a quarrel between father and son about the treachery, Ubayd would end up murdering his father in anger, leaving behind the dagger he used.
In 1499 CE, Ubayd and his Templar handler, Garza, begun abducting Assassin allies in the city and handing them over to the Spanish Inquisition, attracting the attention from both the Spanish Assassins and Najma, now a member of the Libyan Brotherhood. They would rescue their allies from the Ubayd, but much to Najma's ire, he would escape, forcing the Assassins to retreat to safety in the Alhambra fortess.
In the Alhambra, Garza and Ubayd argued about their actions, with Ubayd regretting both the pain he inflicted in Granada and the murder of his father, before Garza stabbed his charge and left Ubayd to bleed to death as Najma arrived. Ubayd would admit to his sister that he was a fool to trust the Templars, and asked that she set things right, for Granada, before collapsing on the stone tiles. She remarked to the Spanish Assassins that accompannied that Ubayd deserved a better death, even after all he had done, before giving chase to Garza.