In 1575 Fyodorov, now in the service of Prince Konstanty Wasyl Ostrogski, was placed in charge of the Derman Monastery near Dubno; in 1577–9 he established the Ostrog Press, where, in 1581, he published the Ostrog Bible in Church Slavonic - the first full version of the Bible printed in moveable type, as well as a number of other books. Fyodorov returned to Lviv after a quarrel with Prince Konstantyn Ostrogski, but his attempt to reopen his printing shop was unsuccessful. His printing facilities became the property of the Lviv Dormition Brotherhood (later the Stauropegion Institute). The brotherhood used Fyodorov's original designs until the early 19th century.