Borovoy's articles on the subject first came under attack from the anti-semitic circles in Soviet academia, because his research refuted the label of cowardice and timidity commonly applied to the Jews by the anti-semites. Borovoy demonstrated that Jewish society in Poland became polarized due to a large stratum of destitute Jews that were marginalized by the Qahal, and these Jews were likely to lapse and seek their fortunes with the Cossacks. Later Borovoy was criticized by some Jewish circles unwilling to admit the class-related antagonism that made possible Jewish presence on the Cossacks' side. There are many known instances of Jews joining Cossacks in the era that preceded the Destruction of Sich in 1775. One notable case is Simon Chernyavsky who was baptised at the Sich in 1765. He later served as the Sich emissary to the court of Empress Catherine II. Moisey Gorlinsky served the Sich as an interpreter, and Ivan Kovalevsky (who was already baptised prior to his arrival at the Sich) reached the rank of a colonel. Some Jews joined cossacks as teenage fortune seekers, one such was Vasyl Perekhryst, son of Aizik, who joined the Host in 1748. Another Jew received exactly the same surname in baptism at the Sich two years later. Ivan Perekhryst was abducted with his entire heder class during a Cossack raid in 1732. Yakov Kryzhanovsky became a Cossack before 1768, he also served as a deacon at the Sich church. He was literate in many languages, and distinguished himself under the command of Petro Kalnyshevsky during the Russo-Turkish War of 1769-1774. In the ancient epics known as "dumy" sung by the Ukrainian kobzari there is a reference made to a colonel named "Matviy Borokhovych" (1647), whose family name (meaning "son of Baruch") indicates Jewish origin. Susanna Luber's study of registration books of the Registered Cossacks contain many surnames that indicate Jewish origin. Cossack families of Jewish origin include Hertzyk, Osypov-Perekhrest, Perekhryst, Kryzhanovsky, Markevych/Markovych, Zhydenko, Zhydok, Zhydovynov, Leibenko, Yudin, Yudaev, Khalayev, Nivrochenko, Matsunenko, Shabatny, Zhydchenkov, Shafarevich, Marivchuk, Magerovsky, Zrayitel' and others.