Btw, the PoD was that a particularily daring Crimean Tartar raid in Lithuanian territory took place in the early 17th century. This strenghthened the Lithuanian faction that wanted an union with Russia, and thus the Lithuanians agreed, as they nearly did in OTL, to crown Ivan IV's son, also Ivan, as the Grand Duke of Lithuania, keeping his right of inheritance. War of Lithuanian Succession followed, and in the end, despite Sweden's intervention on the Polish side, the Russians won for numerous reasons, also expanding into Livonia. After the defeat, Poland's crisis of faith worsened and the Reformation gained a stronghold in many parts of the country; furthermore, the union between Sweden and Poland was much more lasting than in OTL. Eventually, when this world's equivalent of the Thirty Years War begun, Russia-Lithuania was on the Catholic side, but the combined strenght of Sweden-Poland and France proved enough to crush the Catholics. Gustavus II of Sweden-Poland founded a short-lived greater Protestant empire in Northern Europe; after his death, it fell apart, and the union of Sweden-Poland ended as well.
A mark of a true warrior, never surrender. 
