[1] Ermengol began his episcopate by reforming the cathedral canons along the lines of the life of Saint Augustine, as well as granting them lands in the shires of Vallespir, Cerdanya, and Alt Urgell.

In 1012 he travelled to Rome for an audience with pope Benedict VIII,[3] who confirmed the possessions of his bishopric as well as its jurisdiction, including the one over the county of Ribagorza.

In 1017, Ermengol was involved in the establishment of the bishopric of Roda de Isábena,[4] consecrated a certain Borrell as bishop, and received recognition from the latter of his superiority in the ecclesiastical hierarchy.

Ermengol is also credited with having led the Christian military expedition that wrested the Guissona plain from the Islamic Taifa of Zaragoza around 1020.

He died in 1035 while assisting in the building of a bridge near El Pont de Bar village.