A decisive event not only for Polish and Lithuanian history, but also for the history of the whole of Central and Eastern Europe was the Union of Kreva in 1385. This not only decided upon the marriage of the Grand Duke Jogaila to Queen Hedwig of Anjou in Poland. Furthermore, the Union of Kreva – in addition to the establishment of a new dynasty, that of the Jagiellons – also formed the cornerstone for the increasingly interwoven history of Poland and Lithuania until the end of the eighteenth century, since it heralded an era of successive Polish-Lithuanian personal unions which favoured the political, economic, and also cultural entwinement of both countries. This chapter is devoted to the geographic horizon of knowledge in general, and travel reports in particular, in these two countries, which were so politically and culturally intertwined from the fourteenth century onwards. Discussing the earliest beginnings of chorographic writing from the early Middle Ages to the Renaissance humanist period, I would like to end this overview with the aforementioned, caesura-like Union of Lublin, providing only a brief glimpse of subsequent pre-modern era Polish-Lithuanian travel accounts.