@jespah,
Yep,
Henry Plantagenet, the young king was the son of Henry II Plantagenet, king of England, and Alienor of Aquitaine.
The latter was the former wife of Louis VII of France.
Their marriage was annulled and she married Henry II.
Louis VII then married Constance of Castile and fathered Marguerite Capet.
Marguerite married Henry the young king.
Alienor of Aquitaine then became mother-in-law of her first husband's daughter.