I don't understand your comment about having the reference to the Parisian chapel in the history section as being confusing. Louis IX never went near the reliquary, but he is mentioned there, and the way you would have the article gives no idea about his having built it. That seems the logical spot to mention his chapel.
Also, "royal" does not apply to a duke, only to the king, so there is no issue of confusion with my phrasing. The phrase as you keep putting it is simply poor grammar. Perhaps slapdash is in the eye of the beholder.