Charles the Fat
In May 878, she and her husband sheltered Pope John VIII, who was taking refuge from the Saracens, in Arles. After her husband's coup d'état in October 879, she helped defend his cities from her Carolingian relatives. In 880, she successfully defended Vienne itself, the capital, from the combined forces of Charles the Fat and the co-ruling kings of France, Louis III and Carloman. In August 881, the newly crowned Emperor Charles the Fat pillaged and burned Vienne, forcing Ermengard and her children to take refuge in Autun with her brother-in-law Richard, Duke of Burgundy. Meanwhile, Boso fled into Provence.