(Luka Zhidyata), who was appointed to his office by Yaroslav; and that
St. Feodosi Pechersky was fond of conversing with learned Jews on
matters of theology.[16] On the other hand, the efforts of the Jews were
not without success. The baptism of the pious Olga marks an era in
Russian Christianity, the beginning of the "Judaizing heresy," which
centuries of persecution only strengthened. In 1425, Zacharias of Kiev,
who is reputed to have "studied astrology, necromancy, and various other
magic arts," converted the priest Dionis, the Archbishop Aleksey, and,
through the latter, many more clergymen of Novgorod, Moscow, and Pskov.
Aleksey became a devout Jew. He called himself Abraham and his wife
Sarah. Yet, strange to say, he retained the favor of the Grand Duke Ivan
Vassilyevich, even after the latter's daughter-in-law, Princess Helena,
his secretary Theodore Kuritzin, the Archimandrite Sosima, the monk
Zacharias, and other persons of note had entered the fold of Judaism
through his influence.

The "heresy" spread over many parts of the empire, and the number of its
adherents constantly grew. Archbishop Nikk complains that in the very
monastery of Moscow there were presumably converted Jews, "who had again
begun to practice their old Jewish religion and demoralize the young
monks." In Poland, too, proselytism was of frequent occurrence,
especially in the fifteenth and sixteenth centuries. The religious
tolerance of Casimir IV (1434-1502) and his immediate successors, and
the new doctrines preached by Huss and Luther, which permeated the upper
classes of society, rendered the Poles more liberal on the one hand, and
on the other the Jews more assertive. We hear of a certain nobleman,
George Morschtyn, who married a Jewess, Magdalen, and had his daughter
raised in the religion of her mother. In fact, at a time when Jews in
Spain assumed the mask of Christianity to escape persecution, Russian
and Polish Christians by birth could choose, with little fear of danger,