A special place in the work of B. P. Hashdeu is occupied by the historical monograph "Ion-Voivode the Fierce," written by him on the basis of lengthy research begun in his student years. This mass publication does not include 324 footnotes on historical literature published in the XV-XVIII centuries. in various European and ancient languages, which he owned since his youth. For the modern reader, some of Hashdeu's assessments, for example regarding Ivan the Terrible or the origin of the Zaporizhzhya Cossacks, are largely outdated, but in general, Irn-Voeioda Lugy is of great scientific and literary value.