Spanning nearly 900 years, the Middle Ages saw significant changes in the relationship between humans and falcons. During this period, falconry reached its peak before gradually declining. Growing interest in falcons led to a surge in both specialized and literary publications that compiled contemporary knowledge of various falcon species. In fact, there are several sources of information on falcons, including subfossils, bestiaries, falconry treatises, and management catalogues. However, these sources are difficult to compare and often inconsistent. The importation of exotic falcons into different regions, combined with frequent misidentifications, led to confusion about their historical distribution. As falconry developed, so did the standardization of species names, aided by the introduction of technical terms. However, species that were either common or less important in falconry left little evidence in historical records. The increasing capture of wild falcons, particularly the gyrfalcon, likely had a significant negative impact on nesting and migrating populations. Despite these challenges, the knowledge acquired during this period was instrumental in establishing the foundations for classifying falcons within the emerging field of ornithology.