The –Lithuanian–Polish–Lithuanian–Muscovite Commonwealth was a proposed state that would have been based on a personal union between the Polish–Lithuanian Commonwealth and the Czardom of Russia. A number of serious attempts by various means to create such a union took place between 1574 and 1658 and in the late 18th century, but it never materialized because of the incompatible demands from both sides.
The proposed union is known in Polish as the Triple Union (unia troista) and has also been called the Polish–Russian Union (unia polsko-rosyjska) or the Polish–Muscovite Union (unia polsko-moskiewska).
Rationale
Proponents of such a union among the Polish nobility, including the influential secular thinkers Jan Zamoyski and Lew Sapieha, had listed several arguments in its favour: peace on the turbulent eastern border, a powerful military ally and relatively sparsely-populated territories (compared to the Polish Crown) for colonisation and serfdom. The idea was also supported by the Jesuits and other papal emissaries, who never ceased to entertain the idea of bringing Eastern Orthodox Russia into the Catholic fold. Some of the Russian Boyars found the proposal attractive (like Boris Godunov, a supporter of Czar Feodor I's candidacy) for various reasons, such as the fact that the Golden Freedoms of the Commonwealth, if applied in Russia, would weaken Czar's power and thus grant them a much higher status than enjoyed previously.
The proposals then revolved around introducing a personal union between the Commonwealth and Russia and various economic and political agreements (elimination of trade barriers, free movement of people etc.) up to the creation of one country by using the framework of that led to the creation of the Polish–Lithuanian Commonwealth in the first place (Union of Lublin of 1569). However, all proposals presented by the Polish side were rejected by the Russian Czar. The most promising negotiations took place during 1600, when a Polish diplomatic mission, led by Lew Sapieha, arrived in Moscow. Sapieha presented to Boris Godunov an elaborated idea of a union between Poland–Lithuania and Russia. The subjects of both rulers were to be free to serve the other ruler, travel to the other country, contract marriages with the other ruler's subjects, own land and go study in the other country.
Although Moscow was willing to agree to some parts of the proposed treaties (like extradition of crime suspects), it strictly opposed points on religious tolerance (non-Orthodox religions, especially Catholicism, were persecuted in Russia, unlike in Commonwealth, which allowed all faiths to be preached) and free movement of people (according to Polish scholars). To transform the Russian Czardom into a republic modelled on the Polish–Lithuanian Commonwealth would have proven to be a too ambitious project. Many Russians were afraid of Polonization, which was already occurring with the Lithuanian and the Ruthenian nobility, and a growing danger stemming from the increasing number of peasant and even noble refugees escaping the Russian Empire, to which Russian Czar Ivan responded with the policy of violent repressions, the so-called oprichnina. The Union of Brest of 1596 was a further argument for the Orthodox opponents of the closer ties between Russia and the Commonwealth, who argued that it was the prelude to the Catholicisation of Russia.