The book was conceived as a source compendium, which – for the first time – includes archaeozoological data collected from publications and unpublished reports, as well as and archaeozoological studies from as many sites as possible. As a result, for the first time in Polish archaeozoology and archaeology, such an extensive catalogue devoted to horse remains, as well as live stocks used in the Middle Ages on Polish lands, was collected. To do this, several key steps had to be taken. First, a working database – ArchaeoEquus – was constructed using the Access program in MS Office. It turned out to be a fundamental tool not only for collecting all kinds of data on bones, skulls and skeletons of horses, but – above all – for managing these data, making queries and preparing tabular summaries. Thanks to it, it was possible to unify the often divergent chronological and contextual information contained in publications from the past century. It also made it possible to prepare the three catalogues that constitute the content of this book. They include basic statistics of horse remains in stratigraphic, chronological and social contexts. The finds of skeletons and skulls were also listed for the first time. For the first time, data on palaeogenetics were added, indicating the coat colour of horses in the Middle Ages. So far, these are the most numerous figures in Europe. The presented data should be treated as a starting point for the creation of analytical and synthetic work, taking into account the horse not only in the local Slavic context but also more broadly in Europe.