Polish–Lithuanian–Muscovite Commonwealth
The second proposal was made after the death of Tsar Ivan, as Feodor I was made Czar of Russia. After the Polish king's death, Feodor sent a diplomatic mission to the Polish-Lithuanian Commonwealth. The Lithuanians supported him, but Poland asked for things such as Feodor becoming a Catholist, which the Tsar did not want to do. After the next Polish king was elected, Sigismund III Vasa, he asked to become the Tsar of Russia. However, by the time the proposal made it to Moscow, a new Tsar took control of Russia.