Combining Historical Maps, Travel Itineraries and Least-Cost Path Modelling to Reconstruct Pre-Modern Travel Routes and Locations in Northern Tigray (Ethiopia)

Abstract

Investigating long-distance travelling routes is crucial for understanding both historical decision-making processes as well as possible regional points of interest that may have been lost in the course of time. Located in the northern Ethiopian highlands, the city of Aksum was the starting and return point for both, Ethiopian, Arabian, and European travellers on the north-south passage to Cairo, Jerusalem or Europe, at least from the fifteenth century onwards. We extracted locations from travel itineraries from the fifteenth and sixteenth centuries and analysed historical maps from the fifteenth to the twentieth centuries. This data was used to calculate several least-cost paths (LCPs). Results suggest that route planning in historical times was in some cases very cost effective, while in others, visiting specific locations may have played a major role in path selection. Additionally, LCPs based on historical waypoints reveal several remarkable historical locations along their way.