There and Back Again: Mapping 43 Great Journeys and Grading the Evidence That They Happened

Popular maps of great journeys draw the Phoenician circumnavigation of Africa, St Brendan's voyage and the circumnavigation of Magellan and Elcano in the same confident ink. This note maps 43 journeys by travellers and expeditions from about 600 BC to 1947, out and back, and grades each by the evidence that it happened. Each route is an ordered chain of named stops (405 in all) taken from the English Wikipedia article on the journey, with the article and section, the source of the coordinates and a confidence rating recorded for every stop. Each journey is graded Proven (archaeology, physical remains or several independent records), Probable (one good written source), Disputed (serious scholarly argument) or Legend (myth, legend, oral tradition or speculation), and classed by whether its party came home. Of the 43 journeys, 18 are proven, 11 probable, 7 disputed and 7 legends. Evidence thins sharply with age: 7 of the 31 journeys that began before 1450 are proven, against 11 of the 12 that began later, and every legend is earlier than 1450. The grade is visible in the geometry: 3% of stops on proven journeys are conjectural, against 62% on legends. 22 parties came home whole, 9 in part, 7 never, and for 5 the outcome is unknown. Of 21 passages dated at both ends, the 9 under sail made a median 128 km a day. In the six cases where an article states a comparable distance, the drawn routes come to 71% to 116% of it. Interactive version: https://tristan-hotham.github.io/there-and-back-again/. Data and code: https://github.com/Tristan-Hotham/there-and-back-again. Blog post: https://blog.tristanhotham.com/2026/10/27/there-and-back-again/.