Gluck retained this style, also, in his following works, which need be merely mentioned: the perfected serenade "Tetide" (1749), given in the theatre of Castle Charlottesburg at Copenhagen at a birthday fête for the Crown Prince, afterward King Christian VII.; also the operas written for Rome and Naples, "Telemachus" (1749) and "La Clemenza di Tito" (1751) by Metastasio, both noteworthy, in that Gluck, later, availed himself of several of their numbers in the masterpieces of his Parisian epoch. These were followed by a long list of similar works, for Gluck displayed, even then, a restless activity, though in 1750 he married, and with his Marianna, a daughter of the rich Venetian merchant Pergin, experienced all the joy of a happy marriage which remained undisturbed till his death. Two impulses in the next decade of Gluck's activity deserve special mention; one was his eager interest in literature. "Gifted by nature with as great a love for literature as for music," says his biographer Anton Schmidt, "he now worked with incessant energy in this province as well. Though somewhat late, he applied himself to a thorough study of Latin and French and to poetry. He made the acquaintance of the most distinguished men of science, that through intercourse with them and in the companionship of good books he might cultivate the ideas which had so long been ingrafted in his nature concerning the mighty influence of music and its close connection with poetry, of which at this time but few had even dreamed."--"C. W. Ritter von Gluck," p. 79.