Set in the period approaching the Massacre of St Bartholomew's Day this is a tale of lovers separated by an arranged marriage, of greed, innocence and jealousy. If the history of the wealthy seems rather frenetic it was never more so than in this era (a mixture perhaps of more wine than water and the nearness of death).
The film is beautifully set in its era using the Comte de Chabannes, a retired soldier, as an example of its rational side. It features the usual historical cast: Guise, Anjou (very convincingly played), and the Queen Mother; all well acted in splendid costume and sets, not quite the equal of Vatel but then the monarchy was not as wealthy as that of Louis. However, within this setting the story is the old, old, one of unrequited love. Lambert Wilson as the almost Don Quixote (he even has the hat) Comte de Chabannes, Mélanie Thierry as the child-like but beautiful Princesse (at times with an almost Bardot look), Grégoire Leprince-Ringuet as the shambling, decent but jealous husband, and other excellent performances just add to a piece whose general trajectory is doomward.
I think it will be a mite too long for many. Watching La Reine Margot before will also help you with understanding the "runners and riders" of the Wars of Religion.