During the minority of Louis XV., while the Duke of Orleans was Regent of France, a young Flemish nobleman, the Count Antoine Joseph Van Horn, made his sudden appearance in Paris, and by his character, conduct, and the subsequent disasters in which he became involved, created a great sensation in the high circles of the proud aristocracy. He was about twenty-two years of age, tall, finely formed, with a pale, romantic countenance, and eyes of remarkable brilliancy and wildness. He was of one of the most ancient and highly-esteemed families of European nobility, being of the line of the Princes of Horn and Overique, sovereign Counts of Hautekerke, and hereditary Grand Veneurs of the empire. The family took its name from the little town and seigneurie of Horn, in Brabant; and was known as early as the eleventh century among the little dynasties of the Netherlands, and since that time by a long line of illustrious generations. At the peace of Utrecht, when the Netherlands passed under subjection to Austria, the house of Van Horn came under the domination of the emperor. At the time we treat of, two of the branches of this ancient house were extinct; the third and only surviving branch was represented by the reigning prince, Maximilian Emanuel Van Horn, twenty-four years of age, who resided in honorable and courtly style on his hereditary domains at Baussigny, in the Netherlands, and his brother, the Count Antoine Joseph, who is the subject of this memoir. The ancient house of Van Horn, by the intermarriage of its various branches with the noble families of the continent, had become widely connected and interwoven with the high aristocracy of Europe. The Count Antoine, therefore, could claim relationship to many of the proudest names in Paris. In fact, he was grandson, by the mother's side, of the Prince de Ligne, and even might boast of affinity to the Regent (the Duke of Orleans) himself. There were circumstances, however, connected with his sudden appearance in Paris, and his previous story, that placed him in what is termed "a false position;" a word of baleful significance in the fashionable vocabulary of France.