In 990 , the small pagus of Berga was detached from it and granted to Cerdanya .
Throughout the tenth century , Osona remained tied to Barcelona , except for the brief rule of Ermengol from 939 to 943 .
In 990 , the small pagus of Berga was detached from Osona and granted to Cerdanya .
Throughout the tenth century , Osona remained tied to Barcelona , except for the brief rule of Ermengol from 939 to 943 .