This thesis explores the nature of the late medieval European worldview in the context of the thirteenth- and fourteenth-century European journeys to Asia. It aims to determine the precise influence of these journeys on the wider European Weltbild. In lending equal weight to the accounts of the eastward travellers and the sources authored by their counterparts in Europe, who did not travel to Asia, the present study draws together two related strands in medieval historiography: the study of medieval European cosmology and worldview, and the study of medieval travel and travel literature. This thesis treats the journeys as medieval Europe’s interaction with Asia, outlining how travellers formed their perceptions of ‘the East’ through their encounters with Asian people and places. It also explores the transmission of information and ideas from travellers to their European contemporaries, suggesting that the peculiar textual culture of the Middle Ages complicated this process greatly and so minimised the transfer of ‘intact’ perceptions as the travellers originally formed them. The study contends instead that the eastward journeys shaped the late medieval European world picture in a different way, without overturning the concepts that underpinned it. Rather, this thesis argues, thirteenth- and fourteenth-century eastward voyages subtly altered how Europeans were inclined to understand these underpinning concepts. It suggests that the journeys intensified and made the concepts more immediate in Europeans’ minds and that they ‘normalised’ travel itself to the point where it became an essential part of the way Europeans could most readily make sense of the vast and kaleidoscopic world around them.