Complex sentence: Geoffrey VI (Goeffroy VI) (d.6 February 1250), Viscount of Châteaudun, son of Geoffrey V, Viscount of Châteaudun, and Adelicia de Nevers, probably daughter of William IV, Count of Nevers, and Eléonore, Countess of Vermandois.
Split into simpler sentences: Geoffrey VI (Goeffroy VI) (d.6 February 1250), Viscount of Châteaudun, son of Geoffrey V, Viscount of Châteaudun, and Adelicia de Nevers. Although Adelicia's ancestry is not precisely known, she is likely the daughter of William IV, Count of Nevers, and Eléonore, Countess of Vermandois.