Born in the mid-ninth century in Baghdad, Iraq, his father Judah ben David was Exilarch from 840-857, and a fifth-generation descendant of Bostanai.
This ultimately resulted in a boycott by Kohen Tzedek's wealthy and influential friend, Joseph ben Phinehas, who convinced Abbasid Caliph Al-Muqtadir to depose Mar Ukba, which he did in 917.
However, after the young Caliph moved to his summer palace in Safran, Mar Ukba devised a scheme to win the royal favour by meeting Al-Muqtadir's secretary daily in his gardens and greeting him with the recitation of beautiful verses of poetry.
However, only a few months after his reinstatement, Kohen Ẓedeḳ and his friends once again succeeded in securing his deposition and banishment from the country.
Following this, Mar Ukba moved to Kairouan, Tunisia, where he was received with great esteem as a member of the House of David.