Immediately after his investiture, the Emperor Lothair II descended to Italy to thwart the pretensions of Roger II of Sicily who wanted to subdue the southern Italy.
On the river Tronto, William did homage to Lothair and opened his countdom, along with the strategic town of Termoli, to the Imperial Army.
Lothair, after an easy victory against King Roger, came back to Germany at once, but died while crossing Alps Mountains.
Roger, then, gathered a larger army and invaded southern Italy again, this time succeeding in his campaign.
Twenty years later the countdom of Loritello was given to the family Bassunvilla.