In 869, the Carolingian and Byzantine Empires started discussing an alliance to defeat the Saracens in southern Italy. During these discussions, the notion of a stronger alliance came up, by marriage of Ermengard to Constantine, the eldest son of Emperor Basil I. Constantine had been named co-emperor with his father, and was being groomed for that position.
But now we enter highly suspect territory. To start with, we do not know the birth years of either Ermengard or Constantine. Were they old enough to truly marry? Or was this a more of a "child engagement" plan as we have seen in other political alliances through marriage? Some historians claim they were married; some claim there is no evidence for it and the plan never went beyond announcing the betrothal.
The Annales Bertiniani (Annals of Abbey of St. Bertin, covering years up to 882) referred to Ermengard in 879 as filia imperatoris Italiae et desponsata imperatori Greciae ("daughter of the emperor of Italy and engaged to the emperor of Greece"), but they also say she was engaged to Basil, so we aren't sure how accurate the writer was. Also, 879 is the year that Constantine died unexpectedly, with no chronicle suggesting that he had heirs and no suggestion that Ermengard was a widow.
In fact, by 879 she was already married to someone else, despite what other chronicles may have recorded. Some time in the first half of 876, she was married to Boso of Provence (pictured above; there are no reliable images of Ermengard). Boso (c.841 - 887) was a Frankish nobleman who, in 879, became King of Lower Burgundy and Provence.
In 878, Ermengard and Boso sheltered Pope John VIII when he had to flee Rome because of Saracens. In papal correspondence between Pope John and Ermengarde's mother, Engelberga, he mentions the good impression the couple made on him. They had three children. A daughter named Engelberga after Ermengarde's mother married William I, Duke of Aquitaine, founder of Cluny Abbey. There was another daughter of whom we are not certain, but some believe she was Guilla of Provence, who was consort first to Rudolf I of Upper Burgundy (making her possibly the mother of King Rudolf II of Burgundy) and later to Hugh of Arles, border count of Provence.
They also had a son, Louis the Blind, whose story includes a marriage link that become as confusing to historians as his mother's, if not more so. We'll check that out tomorrow, and lament how inaccurate our historical records truly are once we go back a millennium. See you then.
