The drawing is from the 1815 French volume Illustrations de L'Illyrie et la Dalmatie. It shows an Uskoken after an engraving by the Leipzig illustrator Christian Geißler (1770–1844). Uskoks (Slav. uskočiti) was the name given to a militarily organized association composed mainly of refugees from Ottoman-occupied territories. As free soldiers of the Roman Catholic faith, they operated between the spheres of interest of the Habsburg Empire, the Republic of Venice, and the Ottoman Empire.
Christian Geißler (1770–1844), Uscoki, lithograph, 10 cm x 7 cm, 1815; source: Gallica/ Bibliothèque nationale de France, public domain.