https://en.wikipedia.org/wiki/Ermentrude_of_France

Ermentrude was the daughter of Louis the Stammerer, king of France and his second wife Adelaide of Paris whom he married in February 875 with official sanction. Louis had secretly married as his first wife Ansgarde of Burgundy but the marriage was annulled prior to his marriage with Adelaide. After the death of Louis, the struggle for power in the kingdom probably led to Ermentrude's marriage to someone for whom records are scant, whereas usually the marriage of daughter of a king is to a well known noble. Ermentrude's daughter, Cunigunda, first in 909 married Wigeric, count of Bidgau and count palatine of Lotharingia, then in 922 married Ricuin, count of Verdun .