Ever since the conclusion of the Quadruple Treaty, Louis Philippe had been quietly endeavouring to improve his relations with the absolute Powers, in general, and with Austria, in particular. Early in the year 1835 he appears to have embarked, without the knowledge of his ministers or of Sainte-Aulaire, the French ambassador at Vienna, upon a confidential correspondence with Metternich.[373] Without doubt, his flattering advances to the Chancellor were made with the hope that a marriage might be arranged between his eldest son, the Duc d'Orléans, and an Austrian Archduchess. Neither Broglie nor Sainte-Aulaire shared the King's illusions on that subject. Broglie was firmly convinced that there could be no intimacy between the Monarchy of July and the Northern Courts, and it was chiefly on that account that Louis Philippe had been so anxious to drive him from office. But, whilst Louis Philippe had frequently been annoyed by the independence and uncompromising honesty of the _Doctrinaire_ Duke, he had always admired the resourcefulness and political adroitness of M. Thiers. For some time past M. Thiers had been desirous of obtaining the portfolio of Foreign Affairs, and he appears to have satisfied the King that, were it to be confided to him, he would promote the dynastic object which was constantly in His Majesty's mind. He was, it was said, greatly attracted by the prospect of raising "the matrimonial blockade" which the Legitimists exultingly declared had been established round the Orleans throne.[374]