 A French envoy sent in return with Pope John's blessing later in the year, however, found Byzantium beset with civil war, and negotiations floundered.The death of Charles the next year prevented any French intervention in Byzantium.Charles IV died in 1328 at the Château de Vincennes, Val-de-Marne, and is interred with his third wife, Jeanne d'Évreux, in Saint Denis Basilica, with his heart buried at the now-demolished church of the Couvent des Jacobins in Paris.