In 1311 the mists which obscure the greater part of Dante's life in exile are dispelled for a moment, by three letters of unquestioned authenticity, and we gain a clear view of the poet. In 1310 Henry of Luxemburg, a man who touched the imagination of his contemporaries by his striking presence and chivalric accomplishments as well as by his high character and generous aims, "a man just, religious, and strenuous in arms," having been elected Emperor, as Henry VII., prepared to enter Italy, with intent to confirm the imperial rights and to restore order to the distracted land. The Pope, Clement V., favored his coming, and the prospect opened by it was hailed not only by the Ghibellines with joy, but by a large part of the Guelfs as well; with the hope that the long discord and confusion, from which all had suffered, might be brought to end and give place to tranquillity and justice. Dante exulted in this new hope; and on the coming of the Emperor, late in 1310, he addressed an animated appeal to the rulers and people of Italy, exhorting them in impassioned words to rise up and do reverence to him whom the Lord of heaven and earth had ordained for their king. "Behold, now is the accepted time; rejoice, O Italy, dry thy tears; efface, O most beautiful, the traces of mourning; for he is at hand who shall deliver thee."
The first welcome of Henry was ardent, and with fair auspices he assumed at Milan, in January 1311, the Iron Crown, the crown of the King of Italy. Here at Milan Dante presented himself, and here with full heart he did homage upon his knees to the Emperor. But the popular welcome proved hollow; the illusions of hope speedily began to vanish; revolt broke out in many cities of Lombardy; Florence remained obdurate, and with great preparations for resistance put herself at the head of the enemies of the Emperor. Dante, disappointed and indignant, could not keep silence. He wrote a letter headed "Dante Alaghieri, a Florentine and undeservedly in exile, to the most wicked Florentines within the city." It begins with calm and eloquent words in regard to the divine foundation of the imperial power, and to the sufferings of Italy due to her having been left without its control to her own undivided will. Then it breaks forth in passionate denunciation of Florence for her impious arrogance in venturing to rise up in mad rebellion against the minister of God; and, warning her of the calamities which her blind obstinacy is preparing for her, it closes with threats of her impending ruin and desolation. This letter is dated from the springs of the Arno, on the 31st of March.