Cossacks of the Grand Duchy of Lithuania (the end of XV century – 1569): A social portrait, Казачество Великого княжества Литовского (конец XV в. – 1569 гг.): социальный портрет

<jats:p>This article attempts to show the social portrait of early Cossacks of the Grand Duchy of Lithuania. Documents are the main source of military service state Cossack’s. The paper analyzes three periods (1502–1503, 1524, 1534–1537) and the characteristic of nature of military service in the GDL. By comparative analysis the author comes to the conclusion that in the first third of the 16th century Cossacks is a real social group. The main social base of the Cossacks was the servants of the boyars. The causes of the formation of Cossacks’ are hiding in social change to GDL.</jats:p>