Her father, King Leopold I, had died December 10, 1865. Upon his accession to the throne, her brother, King Leopold II, sent a special embassy to the court of Mexico to make an official announcement of his reign. The ambassador, General Foury, arrived with his suite on February 14, 1866, and, having fulfilled his mission, departed on March 4. During their brief visit to the capital, the Belgian envoys had been freely entertained by society. It was, therefore, with a thrill of horror that, on the day following their departure, the news came that their party had been attacked and fired upon by highwaymen at Rio Frio, a few leagues from the capital, and that Baron d'Huart, officier d'ordonnance of the Count of Flanders, had been shot in the head and killed. Four other members of the embassy were wounded. Consternation reigned at court. The Emperor went to Rio Frio to see personally to the comfort of the wounded and to bring back the body of Baron d'Huart, whose solemn obsequies were conducted in the most impressive manner. The news of this tragedy, when it reached Europe, must have cast a flash of lurid light upon the true condition of the Mexican empire. During the winter of 1866 Napoleon III sent Baron Saillard upon a special mission to prepare Maximilian for the gradual withdrawal of the French army, and to intimate to him that he must not depend upon a continuance of present conditions. The envoy, however, failed to make upon the prince the impression which it was intended that he should make. Maximilian received him only twice, and rather resented his warnings. His visit only added to the coldness of the young Emperor's relations with the French. Shortly afterward General Almonte was sent to France on a mission, the object of which, was to influence Napoleon to continue his support. The only result of his errand was a communication addressed to Maximilian, dated May 31, 1866. In this Napoleon stated the situation with a frankness the brutality of which aroused the indignation of the court of Mexico. An onerous agreement was nevertheless arrived at, to which necessity compelled Maximilian to subscribe (July 30). By this agreement, half of the revenue derived from the customs of Tampico and Vera Cruz was to be assigned to the French in payment of the debt until the entire outlay made on behalf of the Mexican empire had been repaid. The French, in return, promised to continue their support until November 1, 1867, and to withdraw their army in three detachments, the last of which would embark on that date. The imperial government was thereby deprived of half of its reliable revenue at a time when, in order to maintain its existence under the present stress, large additional resources should have been at its command.* * See Appendix B.