While the exact date is unknown, Lucaris was ordained in Constantinople.[7] In 1596 Lucaris was sent to the Polish–Lithuanian Commonwealth by Meletius Pegas, Patriarch of Alexandria, to lead the Orthodox opposition to the Union of Brest-Litovsk, which proposed a union of Kiev with Rome. For six years Lucaris served as professor of the Orthodox academy in Vilnius (now in Lithuania).[5] In 1601, Lucaris was installed as the Patriarch of Alexandria at the age of twenty-nine.