Invested by Roger II of Sicily on an unknown date, Bohemond's politics centred on controlling the monastery of Casauria.
Bohemond had the support of Robert of Selby, the chancellor of the kingdom of Sicily, in attempting to get control of Casauria.
The abbey, however, requested nullification from Roger in order to elect one Constantine, whom Pope Eugene III deposed.
The situation became more confused when Bohemond besieged Constantine in Casauria, but Pope Anastasius IV told him to quit the monastic conflict.
In 1154, Bohemond, now opposed to the popes, was ordered to attack Adrian IV as a loyal vassal of Roger.