Royal coats of arms of France, ancient and modern, by V.Lastra.design
Excerpts from "Les pleines armes de France: De Clovis au duc d'Anjou" by Hervé Pinoteau:
"At the very end of the 11th century, Louis VII invented the azure coat of arms strewn with gold fleurs-de-lis, derived from his garments adorned with a spiritual cosmos, thus representing the celestial Jerusalem. This creation dates from 1137/1147, as I demonstrated in 1980. A century later, this cosmic meaning was difficult to grasp, and people began to discuss the Trinitarian aspect of the fleur-de-lis."
"In any case, in French legend, celestial symbols are intertwined with signs and insignia from on high: the holy ampulla, conceived in the 8th century and celebrated by Hincmar of Reims, the Oriflamme of Saint-Denis, the triumphant white cross in the 15th century after the appearance of Bayonne, etc., the introduction of the celestial arms delighted our ancestors, all the more so as this fleur-de-lis shield ultimately proclaimed the mystery of our faith, that of the Holy Trinity, in whose name Clovis was baptized: the fleur-de-lis was perceived as Trinitarian in itself, and the reduction of these celestial flowers to three under Charles V or Charles VI was officially linked to the God in three Persons."