Through Fenelon, the influence of Madame Guyon reached and influenced religious circles powerful at court—the Beauvilliers, the Chevreuses, the Montemarts—who followed his spiritual guidance. Madame de Maintenon and, through her, the young ladies of Saint-Cyr, were soon won over to the new mysticism. This was at the height of Madame Guyon's influence, most of all when Fénelon was appointed on 18 August 1688 to be the tutor to the Duke of Burgundy, the king's grandson. Before long, however, the Bishop of Chartres, in whose diocese Saint-Cyr was located, took alarm at the spiritual ideas which were spreading there. Warned by him, Madame de Maintenon sought the advice of persons whose piety and wisdom she valued, and these advisers were unanimous in their rejection of Madame Guyon's ideas. Madame Guyon then asked for an examination of her conduct and her writings by civil and ecclesiastical judges. The king consented that her writings should be submitted to the judgment of Bossuet, Louis-Antoine, Cardinal de Noailles, and of Tronson, superior of the Society of Saint-Sulpice.