[1] He was a Roman consul [2] His parentage is cited first in 1066, when he appeared as Cencio vir magnificus filio quondam Johannes de Imperator.
In 1039, three siblings, Leo, Bernard, and Bona made a donation to Santa Maria Novella as filii quondam Petri Frajapane de Imperator.
His seal appears on a document of Pope Nicholas II investing Abbot Bernard of Farfa with the castles of Tribuco and Arce.
The militantly imperialist Benzone, Bishop of Alba, recorded in his Ad Heinricum imperatorem libri VII that Cencius worked to influence the election of Alexander II in 1061.
In the election of 1085, Cencius advanced Odo of Lagery, the cardinal-bishop of Ostia and future Pope Urban II, as a candidate.