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Hildegard of the Vinzgau was the wife of Charlemagne, a Frankish queen and the mother of the heir to the throne, Louis the Pious. She married Charlemagne in 771 after his first wife’s repudiation.

Explanation:

Hildegard was born in 754; she belonged to the Udalriching family and was the daughter of Gerold of Kraichgau, the Germanic Count. Her mother, Emma, was, in turn, the daughter of Nebe, the Duke of Alemannia. Hildegard’s father had substantial possessions in the territory of Carloman’s dominion.

Carloman was the younger brother of Charlemagne, and his sudden death encouraged the incorporation of his kingdom through the marriage of Charlemagne and Hildegard in 771. In addition, this union was highly significant for the king as it strengthened his position in the eastern territories of the Rhine and provided the support of the Alemannian nobility.

Hildegard became Charlemagne’s second wife at 12 or 13 years old, and this age was considered by the Church to be appropriate for marriage. However, the queen’s health was remarkable as she had eight pregnancies, and none of them finished with stillbirth or miscarriage. Hildegard frequently accompanied her husband on his military campaigns and gave birth to her children during traveling to Aquitaine, Pavia, and Rome. Hildegard of the Vinzgau acquired a solid reputation and was distinguished for her passionate relationship with the Church. She made several generous donations to French monasteries of St. Martin of Tours and St. Denis. Hildegard got religious education and took spiritual advice with the utmost seriousness. She died from the negative effect of the last childbirth in 783. The king arranged for constantly burning candles and regular prayers near her grave. Hildegard is frequently regarded as the mother of emperors and kings as her son succeeded Charlemagne.

Hildegard of the Vinzgau portrait.
Source: https://upload.wikimedia.org