The study, based on a large number of written documents, including still unpublished letters, iconographic sources, as well as the results of 20 years of archaeological excavations conducted under the direction of the author, tells about one of the most significant events of the Liberation War of 1648-1654 - the battle of Berestechka. For the first time, many unique objects of Cossack and peasant life unknown to researchers are introduced into scientific circulation, the organization and armament of the Ukrainian rebel troops are analyzed.