As every one is aware, the art of silk-weaving, though of very early origin in the East, was only introduced much later to the Western world. The Romans obtained a few silk stuffs from Persia, India, and China at an enormous expense; they also had certain insects from which material for highly esteemed fabrics was procured; but until the closing years of the Middle Ages the real silkworm was unknown in Italy, and the details of its first introduction in the West have not yet been fully ascertained. It is related that during the sixth century B.C. two Persian monks concealed some silkworm seed inside their staffs, and thus succeeded in bearing it to Constantinople, where they taught the art of rearing the insects. In this wise the silk trade is supposed to have been originated in the dominions of the Byzantine Empire, and carried thence by Arabs and Mahomedans to Sicily and Greece. When Roger II., Count of Sicily, conquered the Ionian islands, he returned to Palermo with numerous prisoners (1147-48), who greatly assisted the progress of the silk trade there. Thence it easily penetrated to Lombardy and Tuscany; but was first established and perfected in Lucca, all the Florentines being still devoted to the profitable wool trade. The consuls of the Silk Guild--or of Por' Santa Maria, as it was designated in Florence, from the name of its street--are mentioned among other guild-masters in public treaties; but although this craft too may be of ancient date, it certainly began to flourish much later than the rest. Noting the fact that Giovanni Villani makes no allusion to the Silk Guild in his very minute account of Florentine trade and commerce in 1338, we are inclined to believe that it had made very little advance at that period.[347]