Although historians generally have regarded the Mongol irruption of the 7th/13th century into Persia and countries further to the west as an unmitigated disaster, this calamity may be taken as a starting point for this chapter because it in fact served one purpose that can be regarded as beneficial. The Mongol armies may have been motivated solely by lust for conquest and destruction, but even out of their evil sprang a positive development when they rent asunder the veil which had for so long shut off Persia and other Islamic countries from the West. For as a result of the Mongol invasions new contacts between the East and the West became established, though at first only slowly and with all the handicaps of much ignorance on both sides. As the pioneers in establishing this contact between East and West, such as William of Rubruck, the Polos, Marino Sanuto and Friar Odoric of Pordenone, all belonged to the period covered by the previous volume of this series, there is no need to say more here than to state that their achievements were of prime importance, since they showed the way for later travellers to follow. The East was no longer a closed book to the West, but as yet comparatively few pages had been turned. It must be borne in mind when studying the development of contact between Persia and the West that the “traffic” was not merely from West to East; there were also travellers in the opposite direction.