Advocates for a union of Poland–Lithuania with Russia proposed a plan similar to the original Polish–Lithuanian Union of Lublin involving a common foreign policy and military; the right for nobility to choose the place where they would live and to buy landed estates; removal of barriers for trade and transit; introduction of a single currency; increased religious tolerance in Russia (especially the right to build churches of non-Orthodox faiths); and the sending of boyar children for an education in more developed Polish academies (like the Jagiellonian University). However, this project never gained much support. Many boyars feared that the union with the predominantly Catholic Kingdom of Poland and Grand Duchy of Lithuania would endanger Russia's Orthodox traditions and opposed anything that threatened Russian culture, especially the policies aimed at curtailing the influence of the Orthodox Church, intermarriage and education in Polish schools that had already led to successful Polonization of the Ruthenian lands under Polish control.