Ermengarde, or Irmengarde de Hesbaye (born about 778) was the daughter of Count Ingerman, Count of Hesbania (Hesbaye, now in Liège, Belgium) and Hedwig of Bavaria.
Thus, the approximately five-year-old Ermengarde inherited the viscounty of Narbonne, which occupied a strategic place in the politics of Languedoc: it was desired by the Counts of Toulouse, the Counts of Barcelona, the Trencavel viscounts of Carcassonne, and the Lords of Montpellier.
In the same year, Ermengarde witnessed a charter in Vallespir, in the territory of her cousin Ramon Berenguer IV, Count of Barcelona, with whom she must have taken refuge in the face of the threat from Toulouse.
In 1143 Ermengarde was married to a vassal of Roger II, Bernard of Anduze.